A different zelkova

Throughout Philadelphia, you’ll see the Japanese zelkova planted as a street tree, or planted in yards and parks, all over the place.  If you go over by Norris Square in North Philadelphia, just south of the Square, along Howard Street, there’s a row of enormous zelkovas.  Or if you’re in Chestnut Hill, at the triangle of green bounded by Ardleigh, Winston, and East Willow Grove, you’ll also see some large zelkovas.  And just in general, if you go around the city, looking at trees, you’ll see plenty of Japanese zelkovas – they have dark grayish bark, somewhat rough, with an orangey tone underneath, that you can see as the bark above it peels away.  Their leaves are toothed, and come to a bit of a point at the end – they’re shaped somewhat like the leaf on the Breyer’s ice cream logo.  Their branches spread out somewhat, and their canopy makes a nice rounded shape.  They’re tough trees that can live well in the city, and they also grow in an attractive habit – they look nice and they grow well, and so, they’re planted all over the place.  The Japanese zelkova (Zelkova serrata) is an ubiquitous street tree in Philadelphia.

But there is another zelkova in Philadelphia, the Caucasian zelkova (Zelkova carpinifolia) that is rarely, if ever seen.  In fact, the only one that I’m aware of in Philadelphia, and perhaps the only one in the state, and quite likely the only one in the Delaware Valley, is at the Woodlands Cemetery in west Philadelphia, and it looks like this:

Zelkova carpinifolia, Woodlands Cemetery, Philadelphia, PA
Photo courtesy Jessica Baumert

It truly is magnificent – with its upwards reaching branches (that is, its fastigiate growth habit), it looks like a wild upended broom in the wintertime.  Lush foliage in the spring fills its canopy with green that lasts through to the autumn, and in the winter, when it loses its leaves, the fastigiate habit makes for a wonderful structural element in the landscape.  And its gray silvery bark, without the orangey-red underbark of the Japanese zelkova, gives it a subtly rich texture throughout the year.  The branches also fuse with each other, making for an appearance like a strangler fig in the tropics, with the branching and anastomosing strands tangling into wonderful knots.

This fusion is an interesting characteristic, and not wholly uncommon in plants.  Plants are different from animals, in that they have far fewer moving parts than we do.  For animals, cells move with respect to each other – they move around the body, they shift as organs develop, they die, they grow, they can even travel quite far from where they were initiated, for example in the case of blood cells.  An animal cell did not necessarily grow up next to its nearest neighbor, they are moving around so much, and so they need to have a pretty sophisticated system of cell-cell recognition, to make sure that the cell nestled up against them isn’t a parasite, like a bacterium or fungus, as some of their neighbors may be.  And so, we (animals, that is) have immune systems that are pretty good at differentiating self from non-self.  This is good for reducing parasite load, however, it isn’t so good if you want to make a graft – hence the need for immune suppressing drugs when organ transplant surgery is completed.

Plants, however, grow by stacking one cell atop another as they divide and grow, and these cells are cemented together the one against the other as they do this – they grew up next to their neighbors and they’ll live next to them for the entirety of their lives, and after they die, they’ll be stuck there still.  And so, there has been less evolutionary pressure in plants for a tight recognition of self versus non-self – proximity does that job for them.  This isn’t to say that plants don’t have immune systems – they do.  But they are not as tightly controlled as ours, and this means that individual plants can fuse with each other much more readily than animals can.  And this is something that we (humans, that is) take great opportunity with, everytime someone grafts a tree, or a rose.  There is a downside to this, however, too, because it also means that diseases can flow from one plant to another, if a parasitized individual has fused with a non-parasitized one – this is what happened with the elms of North America, as Dutch elm disease arrived.  The trees’ roots had fused under ground, as they grew the one against the other along streets and avenues of the towns of America, and if one tree got sick, then rapidly all the trees in a row got sick, as the causative agent of this disease, a parasitic fungus, traveled along those fused roots.

And so, as with many things, there is a plus and a minus, advantages and disadvantages, to our respective immune systems, and how they spring from our differing developmental protocols, and how they then in turn affect that development as we grow.

And due to that development that allows for that fusion, the rummaging branches of the Caucasian zelkova have a fairyland apperance – like a mazed tangle of upright hair, knotting together, and then unknotting again, reaching Rapunzel like, but towards the sky.

When I first saw this tree at the Woodlands, the one that is pictured above, I’d thought it was very old, this enormous trunk.  It is very very large, and I’d been told that the Caucasian zelkova, this species, was at the Woodlands in William Hamilton’s time.  (William Hamilton was the Philadelphia gentleman and plant enthusiast who owned and cultivated the Woodlands up until the earliest part of the 19th century – he died in 1813, and there is a rich heritage of horticulture and natural history at the Woodlands that continues to this day)  And so from the first time I saw it I assumed that this trunk was somewhere around 200 years old.

This seemed to be supported by other evidence.  In an article I read, that I was pointed to by Joel Fry, Curator at Bartram’s Garden, this tree is discussed.  In 1876, in The Gardener’s Monthly, Eli K. Price, who was the commissioner of Fairmount Park, writes about this zelkova, and mentions it as having been here in Hamilton’s time.  And he and others had been thoroughly impressed with this arborescent spectacle – Price writes, in that same article, about a visit by Charles Sprague Sargent (a Harvard botanist) to Philadelphia, for the celebration of America’s centennial, at which time Sargent visited the Woodlands and marveled at this tree.  Price writes:

“These trees will be cared for and preserved in the Woodlands. What is more important is, that they should be secured to our country by propagation. If seed should appear next Fall, they will be gathered. In the meantime grafting should be attempted. Mr. Sargent is trying it at Cambridge, on English elms. I invite gardeners to get cuttings and try their success.”

Price does not mention if Sargent was successful with those grafts, nor if the legion of invited gardeners were successful with their cuttings, to propagate this tree, or even if they tried at all.

And so, as I looked at this wonderful tree and wondered why something so spectacular wasn’t growing in yards and parks throughout Philadelphia, like its cousin Zelkova serrata does, I thought I understood – this was, I believed, a very slow growing tree, and perhaps difficult to propagate, and it would take a very long time for it to get to this magnificent shape and structure, and so there were pretty good reasons for it not to have been commonly planted, and this, I thought, was why we don’t see it very often around here.

But I was wrong.  Yes, the Caucasian zelkova was at the Woodlands at Hamilton’s time.  This tree, this kind of zelkova, was brought into Europe from the Middle East in the 1780s by Andre Michaux, who had gone to Persia (what we would now call Iran) and collected it and brought it back to France.  At about this same time, William Hamilton, owner of the Woodlands at that time, was in England, visiting from Philadelphia, collecting plants and sending them back home – those plants would not have included the Caucasian zelkova, since it would have only freshly been introduced into Europe.  We’re not sure exactly how it got to the US, and to Hamilton’s estate.  But it may well have been via Michaux – he certainly was at the Woodlands, and he ran nurseries up in Hackensack (in New Jersey) and down in Charleston (in South Carolina) through which he might have imported this tree, and so while we can’t say for sure, we can make a rough approximation that Andre Michaux may well have been the fellow to have brought this tree to us, when it arrived here in the earliest part of the 19th century, or the latest part of the 18th.

But this large trunk now at the Woodlands, the one pictured above, was not from that and then, at least not directly.  As was pointed out to me by Joel Fry, John Harshberger wrote an article on the Woodlands in 1921, in The Garden Magazine, where he mentions these zelkovas:

“Outside of the remarkable Ginkgos, the rarest and largest trees of “The Woodlands,” are four remaining specimens of Zelkova crenata [note: this is an older name for this tree], native of the Caucasus regions. This species was originally planted in two rows forming an avenue of approach to the house. The single remaining tree of the west row near the stable was alive on June 24th, 1916, but is now dead. It measures 14 ft. 8 in. in circumference. In the eastern row, all of the three trees are now dead. These trees measure respectively 12 ft. 6 in.; 12 ft.; and 11 ft. in circumference. They are about 50 tall. Two young sprout trees have appeared between the second and third, which are already 10 ft. tall and promise to become lusty specimens.”

Though we know when that last one died back, it’s not clear when the others died, though we do know that the four mentioned above were here in 1905, as they are mentioned in Benjamin H. Smith’s 1905 “Some Letters from William Hamilton, of the Woodlands, to His Private Secretary” (The Pennsylvania Magazine of History and Biography, Vol. 29, No. 1 (1905), pp. 70-78):

“Only one specimen of the Ginkgo, now the oldest tree of that species in America, still remains in the vicinity of the old mansion ; near by are four large trees of Zelkova crenata, from the Caucasus, now in their old age, and these, with a few ancient English hawthorns, alone remain to attest the ancient glory of the gardens and grounds at The Woodlands.”

There is a photo of one of those original trees, currently in the Samuel N. Baxter collection at Bartram’s Garden (it was shown to me by Joel Fry), with a photograph from the 16th of April, 1920, of Mr. Baxter (he was the chief arborist of the Fairmount Park system at the time) gazing up at at a large trunked (13′ 4″ in diameter!) fastigiate tree – an original Woodlands Zelkova carpinifolia, “just before tree died”, as a label on the back of the photo tells us.  This provides further supporting evidence that those original Caucasian zelkovas are no longer there.

And so, by 90 years ago, the originals were gone.  This one we see now is a root sucker off them, one of the ones mentioned in Harshberger’s article from 1921, and it’s not more then 90 years old.  And it’s enormous, and so it’s not so slow a grower.  And so that is not why it is not planted commonly around here.

But perhaps it can’t be propagated well, and maybe that’s why we don’t see it.  Well, if we visit the McLean Library of the Pennsylvania Horticultural Society and look in catalogs from Meehan’s Nursery, a large one in Germantown, here in Philadelphia, we see that they had this tree for sale in the late 19th and early 20th century.  While it’s not in their 1858 catalog, it is in the 1880 catalog, under the name of Zelkova crenata – under a listing for plants that were “1 to 2 ft”, they went for 50 cents a piece, which wasn’t cheap at that time.  They didn’t sell them in bulk either, only by the piece, which suggests that they didn’t have a lot of them, or at least didn’t think they’d sell a lot of them.  The latter theory is borne out in the 1893 and 1895 Meehan’s catalogs, in which Zelkova crenata is noted as being “Rare in cultivation”, and in the 1896-1897 catalog, in which it’s either upgraded or downgraded, I don’t know which, to being “…not common in cultivation”.  Starting in the 1897-1898 catalog, it starts being sold under a different name, Planera richardii, and it was sold under that name for a few more years.  However, by the 1911 trade catalog, it isn’t there, and in the 1911 retail catalog, Planera is only listed in the back, and it is not described, nor are individual species listed – they are only listed in a footnote as being “in stock”.  The plant is not in the later catalogs – not in the 1916, nor 1917, nor 1923-1924.  Its few decades of being sold by Meehan’s Nursery had passed.  But it had been sold.

This tells us that it can be propagated, and the tree at the Woodlands shows us how well it can grow, how strong it can grow in a city, and just how beautiful it can be.  It’s a marvelous tree that can be propagated well enough to have been in the horticultural trade for a few decades, and it’s a tree that can grow quickly and live for a pretty long time, somewhere around a century, or a bit more, in a cemetery in the midst of one of the largest cities of North America (Philadelphia, that is).

So why isn’t it planted more often?  Why do we see it so rarely?  The only other one that I’m aware of anywhere near to here is one near the Capitol building, on the National Mall in Washington, DC.  Why aren’t there more of them planted in the cities and suburbs of the mid-Atlantic states?

I don’t know.  Its relative, the Japanese zelkova, is an extraordinarily common street tree in Philadelphia, but the Caucasian zelkova is not.   But this is a tree that could be planted, could be propagated for sale and distribution, could be grown in parks and yards throughout Philadelphia – it’s a tree that we don’t see much of, but we could see more of.  We just have to propagate it, plant it, and let it grow.

To read about the importance of cemeteries to urban land management, see here:

https://cemeterylandmanagement.wordpress.com/

To read about some more natural history and open areas in Philadelphia, including cemeteries – see here:

Some Plants and Insects of the Woodlands

The trees of Monument Cemetery

Oakland Cemetery

Wissinoming, including Mt. Carmel cemetery

Cedar Grove

Hunting Park

Feral landscaping (Woodlands and Mt. Moriah cemeteries)

And to read about some other trees, see here:

American elms

“Penn treaty” elms

The saucer magnolia

American Chestnut

The Callery pear

Paulownia tomentosa, the empress tree

London planes and American sycamores

The sophora

Fringe tree

Advertisements

Cedar Grove

There used to be a train station, in the lower northeast of Philadelphia, called Cedar Grove.  It was on Tabor Ave, just a bit southwest of Godfrey Ave, and was on the Frankford spur of the train line that goes to Fox Chase, which is in a bit farther part of the northeast of Philadelphia.  This spur went just about all the way to Frankford Ave, ending at a terminus between Unity and Sellers Streets.  It was a train line that carried freight and also passengers – starting in the late 19th century, it lasted well into the 20th century, going behind the Sears on the Boulevard, along the eastern edge of Northwood Park, and among the houses of heavily populated Frankford.

It also traveled through Cedar Grove.  This was the name of the neighborhood, as well as the train station, and up through the early part of the 20th century, it had open marshes and thickets, and forests with spring wildflowers, and wild flocks of birds filling the sky.

Cedar Grove is just to the east of Tacony Creek and just above the Boulevard, and in the early part of the 20th century it was quite unbuilt.  There were woods there, with beeches and oaks, and poplars and sweetgum and ash trees and sassafras, too, all growing there among each other.  In the spring there were anemones and partridge berries on the forest floor – and hayscented fern was there, as was the trout lily, one of the beautiful wildflowers of the spring, which would’ve come up year after year alongside the mayflower that was there, neighboring side by side with the bellwort (Uvularia sessilifolia) and jack in the pulpits.

Another fern, royal fern, would’ve grown in low wet areas of the woods, and yet another fern, interrupted fern would’ve been a bit higher up.  Royal fern, whose latin name is Osmunda regalis, is in the same genus as the interrupted fern, Osmunda claytoniana.  The interrupted fern, however, likes it a little bit drier than its wetland cousin, and so would’ve been in areas a bit drier – upland and underneath the trees, growing along with and near the wood sedge that would’ve dotted the ground up there.

Dwarf ginseng was also in the woods of Cedar Grove, on the ground, growing among the willow oaks, and poison ivy scrambled there, too.  Pinxter, the azalea with its wild pink flowers, would’ve been a bright beacon in the forest of the early spring.

Beneath the beeches and the oaks were also Dutchman’s pipes, a plant also commonly called by its Latin name, Monotropa.  This is a parasitic plant, it doesn’t make its own sugar, it isn’t green, it doesn’t photosynthesize – it eats sugar that is carried through mycorrhizal fungi, this achlorophyllous plant parasitizing the fungus that in turn has gotten its sugar from a plant with which it is mutualistically symbiotic.

In addition to these forests, there were wide open flats, somewhat wet, in Cedar Grove, with sheep laurel and blueberries, and purple milkwort (Polygala sanguinea), too.  Swamp white oak and black willows made little canopies here and there in these wet areas, as woolgrass (Scirpus cyperinus) nodded in the breeze nearby, bobbing along with the rustling of the narrow leaved and the wide leaved cattails.  Swamp milkweed (Asclepias incarnata) attracted the butterflies, and close to the ground, trailing lightly and low, was the cranberry (Vaccinium macrocarpon).

And there were birds – enormous flocks of blackbirds flew above the flats.   And in the woods Eastern Towhees (which also used to be called, colloquially, “chewinks”) scratched and picked among the leaves, loudly and boldly, with White-throated Sparrows following behind them, picking through their trails.  American Kestrels (also known as sparrow hawks, back in the early 20th century) cruised above the long flat fields of Cedar Grove, and Ovenbirds walked among the forest trees, occasionally flying up to sit in a tree’s branch and sing.

Meadowlarks, now rarely seen in Frankford, used to be in Cedar Grove year round – in the middle of December, in flocks numbering to more than 25, they’d get flushed by a train going by and fly through the air.  And the Winter Wren was out along the train tracks, too, in the icy cold, a little chilled hobo out there in the sleet and snow.

So how do we know all this?  How can I say with such detail what was living and growing in Cedar Grove in the early 20th century, when I wasn’t there and wasn’t until many decades later?  Well, one can reconstruct former ecologies, one can estimate historic plant and animal communities, by knowing habitats of plants and animals, and figuring out, based on climate and soil and hydrology what the habitat of the site would have been in the past, and then, building from that information, one can construct a vision as to what would have been there in the past.  That’s one way to do it, and for most places in the world, that’s really the best you can do.

However, in Philadelphia, we very often have another way to do this – here, we have extensive written records and museum collections, and it’s amazing the level of detail available, documenting what has lived here before.  One might expect there to be records for cultivated plants in parks and gardens, because they were planted by people, and people can keep records.  But there is also extensive and intensive information available on many of the plants that grew without being planted by people, and for the animals that walked and flew among those plants.  Philadelphia’s rich history of natural history is unequalled for supplying this kind of information, and for keeping these records. [Note: There is also a record of a Herring Gull of which “Mr. Wm. Morris Whitaker also secured a specimen October, 1893, on a mill dam at Cedar Grove, Philadelphia, five miles from the Delaware.” from Witmer Stone’s “The Birds of Eastern Pennsylvania and New Jersey” (1894)]

And we can use those records, if we know about them, to learn about what was here before.  Or, if we don’t know about them, we can talk to those that do.  In 1910, Henry S. Borneman read a paper before the Historical Society of Frankford about the birds that were in the area, including Cedar Grove, in the late 19th and earliest 20th centuries.  Over a hundred years later, in 2012, Susan Couvreur and Diane Sadler, of the Historical Society of Frankford today, drew my attention to that work, with its richly detailed description of the bird life of Frankford, and also its discussions of the plants and habitats of the time.

There are also plants from Philadelphia that were, in many years past, collected, pressed, dried, and mounted on paper sheets, that are now deposited at the Department of Botany of the Academy of Natural Sciences of Philadelphia, and these plants that were collected decades ago provide evidence of what is no longer there.  There’s also a list of historic collections of plants from Philadelphia, that was extracted from the Plants of Pennsylvania database maintained by the Morris Arboretum, that was kindly provided to me by Ann Rhoads and Tim Block (botanists at the Arboretum).  This list provides an effective guide to the many collections from Cedar Grove that have been made in the past.

There were collectors in years gone by that allowed me to develop this wonderfully rich description of a site that has changed so much.  Walter Benner collecting sheep laurel (Kalmia angustifolia) on the 8th of July in 1926, in a moist thicket of Cedar Grove.  Samson McDowell, Jr collecting blueberry (Vaccinium corymbosum) in the moist woods there, on the 19th of May 1926.  These collections are now part of the Academy’s collections, and nearly 90 years later, their work allowed me to see first hand the plants that were there when they wandered through those open areas of Cedar Grove.

There are also maps, such as the 1895 and 1910 Bromley Atlases, from the Athenaeum of Philadelphia (available on PhilaGeoHistory.org), that show just how open the area was, how unbuilt it was a hundred years ago, and where the train line that cut through Cedar Grove went.

Taking these records, and applying some additional knowledge of ecology, we can describe Cedar Grove nearly as thoroughly as if we had walked through it ourselves – and a surprisingly detailed picture of this place in the early 20th century can be cobbled together.  Its open marshy areas and its forests, both of them rich with flowers and birds, the train line running through it, trees dotting the flats.  An evocative illustration can be drawn of a landscape that is no longer there.  And perhaps an evocative illustration can also be drawn of a landscape that is yet to be.

Paulownia tomentosa, the empress tree

Paulownia trees are blossoming across the city now.  If you ride the El to Frankford,  northeast out from center city, and you look out over the rooftops, you’ll see bright purple flowers growing on trees, all the way along the way, coming up in vacant lots, or in backyards, or from cracks in buildings high above the ground, or from cracks in the sidewalk down among the feet, with pretty much all of those trees having gotten where they are on their own, or with just the help of the wind.  Or, if you walk the Benjamin Franklin Parkway northwest out from City Hall, you’ll also pass Paulownias there – these ones planted by people, in Logan Circle, halfway up the way to the Art Museum, and though having arrived there with help from humans, they also, just as well, are flowering fully in profusion here in Philadelphia, now.  Anywhere they can get a hold, the Paulownia trees will grow, and the Paulownia trees will blossom, usually in May, or also in April, as they are doing this year.

This tree was originally from Japan, and arrived in Britain in 1840, having arrived in France a few years prior to that. The Paulownia got there because of Philip Franz von Siebold, and it was named for Anna Palowna, the hereditary Princess of the Netherlands, who was also the daughter of the Empress of Russia.  And so it was an empress tree from the very beginning of its nomenclatural life.

Philip Franz von Siebold was a physician from what is now the south of Germany, who worked for the Dutch military in the far east.  Working in Japan in the early part of the 19th century, he was at first restricted in his ability to leave his post and travel around the country because Japan was mostly closed to westerners at the time, but his medical skills ultimately gave him access to areas that others did not have – and so he was able to indulge his passion for natural history, in addition to others.  Taking full advantage of this capacity to collect, Siebold sent back plants and plants and plants upon plants, sending them back home to Europe, and one of those plants was the Paulownia.

And so the Paulownia arrived in France in the 1830s.  Daniel J. Browne, in his 1846 Trees of America, notes that the Paulownia was in the Jardin des Plantes, in Paris, and had hit a height of twenty feet by 1842, with leaves two feet in diameter, and had survived the winter of 1838-1839 “without any covering”.  It had arrived, survived, and thrived.

We know an impressively large amount about how this tree came to be there.  Joseph Henri François Neumann, the man who took care of the hothouses at the Jardin des Plantes in Paris, wrote about the Paulownia, and what he wrote was translated and published in Andrew Jackson Downing’s journal, the Horticulturalist and Journal of Rural Art and Rural Taste, in 1846:

“Some time ago I received a foreign seed, which produced a tree. This tree I kept two years in the hot-house because I had but a single specimen, and I was fearful of losing it.  But soon after finding that the shelter did not suit its habits, I planted it in the open air.  There it found a temperature similar to that of its native country. It soon developed itself with great luxuriance.  The leaves became at least ten times larger than when in the hot house, which was probably too warm for it.  Here it soon showed its flower and fruit and was in fact the fine tree from Japan to which botanists have since given the name of Paulownia imperialis.  I am far from wishing to boast of having naturalized or acclimated it, since we cannot say that its nature has changed, or that it would not have stood at first with the greatest facility in our climate.  But we can say that it finds at Paris almost the same temperature as in Japan, and that it thrives very well here.”

The Paulownia arrived in America soon thereafter.  Daniel Browne (again writing in his 1846 Trees of America) says the introduction of Paulownia to the US was via Parson’s in 1843.  Its presence at the Parson’s Nursery in Queens (NYC) by 1843 is noted in the American Agriculturalist of August 1843, and so we can be reasonably sure it was there, but it most likely also came into the US via other avenues as well.

William Kenrick, writing out of Boston, in his New American Orchardist in 1844 writes of “Paulownia… A new and splendid tree from Japan” and provides the following background:

“At the Garden of Plants in Paris the tree blossomed for the first time early in May 1842 the parent tree of all in France.  In Normandy, the tree, while young, is tender, afterwards hardy.  Such is my account, from the distant but most authentic resources The trees first sent me from France, early in 1842, being lost in the wreck of the ship Louis Philippe, new specimens were again sent early in 1843.”

And so it sounds as though it arrived in Boston at about the same time it would’ve gotten to Parson’s.

Well within twenty years of its introduction, the Paulownia was recognized as the vigorously growing tree it is – in the Transactions of the American Institute of the City of New York for the Years 1859-1860, a discussion is reported in which it is discussed how an inquirer might “prevent his maple trees from being destroyed by worms” and one answer given is “He must give up the Maple and plant Ailanthus.”, to which William Robert Prince, nurseryman of Queens, NYC, adds “Or Paulownia.”

This tree’s speedy growth is something that Thomas Meehan noted in his American Handbook of Ornamental Trees, writing that “It is as rapid a grower as the ailanthus, the wood and trunk of the tree also resembling it”, in 1853.

Andrew Jackson Downing also recognized the similarity to Ailanthus – “The Paulownia is an entirely new ornamental tree very lately introduced into our gardens and pleasure grounds from Japan and is likely to prove hardy here wherever the Ailantus stands the winter, being naturally from the same soil and climate as that tree.”  Downing also writes of the Paulownia: “In its growth this tree while young equals or exceeds the Ailantus …”  (from A Treatise on the Theory and Practice of Landscape Gardening, 2d edition, 1844)

Downing noticed its amazingly fast growth, too – “In rich soils near Paris it has produced shoots in a single season 12 or 14 feet in length.” – but given that rapid expansion who wouldn’t have noticed how speedy it grew?  Downing also records the Paulownia’s flowering time as being about the same as now, “Its flower buds open during the last of April or early in May…” and also that it was “yet very rare”.

Downing believed that if the Paulownia were to end up being as hardy as they “confidently anticipate”, that “it will be worthy of a prominent place in every arrangement of choice ornamental trees.” (the above quotes from Downing are all from the 2d edition of his Treatise, in 1844)

But at this point, no one really knew the plant, and just how large and fast it could grow – Joseph Breck wrote in his Breck’s Book of Flowers in 1851: “To all appearances it will not grow to a very large size in our climate”.

And William Darlington writes in his book “American Weeds and Useful Plants” (2d edition, 1863), that the Paulownia is “A tree of very rapid growth and having a strong resemblance to the Catalpa.  The young trees are remarkably vigorous and bear leaves of an enormous size.  It is a little too delicate for the climate of New York, for three years preceding the present (1858) the flower buds have been very generally killed by the severe winters.  The capsules remain on the tree for a very long time and injure its appearance.”

At its earliest days in the occident, as you might expect, the attributes of this tree were unknown – again from his Book of Flowers in 1851, Breck quotes Andrew Jackson Downing as writing: “When the Paulownia was first introduced into the Garden of Plants, at Paris, it was treated as a delicate green house plant.  It was soon found, however, that it was perfectly hardy on the Continent and in England.”  Nobody at that time knew just how well this tree could grow in the temperate cities of Europe and North America, but they tried it out nonetheless, and found it to be able.  Very able.

The Paulownia, early on after its first introduction into the west, was seen as having enormous potential for horticulture, being a tough, fast growing tree with beautiful flowers, and it was predicted that it would soon be everywhere.

The tree likely came into Philadelphia through Robert Buist, the nurseryman who had a garden called Rosedale in what is now southwest Philadelphia.  Meehan writes of the Paulownia (in the American Handbook of Ornamental Trees, 1853):  “There are many fine specimens, though but recently introduced in some of our streets at Rosedale and many other places in the vicinity.” (thanks to Joel Fry, of Bartram’s Garden, for pointing me towards this quote – Joel also mentions that “This book by Meehan is largely a catalogue and description of the mature trees at Bartram’s Garden ca. 1851. The Paulownia does not seem to have been at Bartram’s then, or at least Meehan doesn’t specifically note it was here.”)

And so the Paulownia was rapidly being planted broadly.   And it was also being planted in places of prominence.  Thomas Meehan writes in his Gardener’s Monthly in September 1882, of the Paulownia:

“One of the first trees, perhaps among the very first trees introduced into the country, is now in Independence Square, Philadelphia. It must be about thirty-five years old. It was one of the first lot imported by the late Robert Buist, and presented by him to the city. It is probably eight feet in circumference, and may be sixty feet high.”

That tree was still there at the end of that century, as Meehan wrote in 1899

“Probably the largest specimen Empress Tree – Paulownia imperialis – in America, is in Independence Square, Philadelphia.  It is one of the first lot introduced into America about fifty years ago, and was a gift to the city by the late Robert Buist, one of America’s famous nurserymen.  It is now eleven feet in circumference, equalling in girth some of the old American Elms that were in the plot before the Revolution.”

But a tree isn’t just a trunk – it also has flowers.  Meehan also wrote, in that 1882 article mentioned above, when he writes about the Paulownia, that “This magnificent tree has been in bloom abundantly everywhere this season”.  He attributes this abundant blooming to attributes of Paulownia floral development: “The flower buds are formed in the autumn and are more or less injured by the winter. The past season being mild the flowers are unusually abundant.”

We, today, here in Philadelphia, had a mild winter this past year, perhaps providing us with pretty much the same thing as Meehan saw in the fall of 1882.   A mild winter that would have led to less frost and cold damage to the overwintering buds means we may well be seeing more blooms than usual this year, in 2012, due to last year’s warm wintry months.

The flipside to this is that the overwintering flower buds of the Paulownia could also be seen as a problem – Thomas Meehan, in his Gardener’s Monthly, in 1865 (volume VII no. 6), writes:

“Upon the rural estate of S.G. Sharpless, Esq., on the Philadelphia and Westchester railroad, one of the finest in Chester county, there is a Paulownia Imperialis Tree, growing very thrifty; it forms blossom buds plentifully every year, but never blooms; and it is supposed that the cutting winds of winter so injure the buds that they cannot expand in spring.”

A similar concern was raised elsewhere, and later – in 1908, Angus Duncan, writing in England, in his book Hardy Ornamental Flowering Trees and Shrubs, sung the praises of Paulownia, but lamented that “Though perfectly hardy in other respects it is unfortunate that the season at which the Paulownia flowers is so early that, unless the conditions are unusually favourable, the flower buds get destroyed by the frost.”

There were other concerns – in another issue of Meehan’s Gardener’s Monthly from 1865 (volume VII, no. 2), Thomas Meehan also recommends “Paulownia, for those who like sweet or showy flowers regardless of an ugly growth.”  So the habit was not necessarily considered attractive.

But into the 20th century, the Paulownia was still fully able to take a place of prominence.  In the 1920s, in Philadelphia, when Logan Circle was set out with plants, this circle having been placed in the midst of the Benjamin Franklin Parkway, the grand boulevard that is our own Champs Élysées, our own reminiscence of France, of Paris, this parkway that is the Philadelphia passage from city to parkland, designed by Paul Philippe Cret to be our cultural boulevard stretching outwards from the center of our town to the heavens of art and nature – when Logan Circle was set like a gem within this diagonal jewelry of a drive, it was set with trees, and those trees were Paulownias.

And those trees lasted for decades – every spring sharing their blooms with the Parkway, and with the Academy of Natural Sciences right across the street, and with the main branch of the Philadelphia Free Library right there on the other side.  These trees were taken down a few years ago, due to concerns related to their old age, and they were replaced shortly thereafter with new Paulownias, and those are the ones that are blooming there now.

But, however, to get back to the past, there were additional problems noted of the Paulownia, in addition to its “ugly growth” and the potential loss of its blooms due to too cold winters or late frosts – something that made this tree so attractive early on, its ability to thrive and survive in our climate, and more precisely in human constructed habitats in our climates, also gave it the potential to spread wildly in our cities, and, perhaps more of a cause for concern, to spread in yards and nearby uncultivated areas.

By 1905, it had “Escaped from cultivation”, as was noted in Ida Keller and Stewardson Brown’s “Handbook of the Flora of Philadelphia and Vicinity”, and even earlier, Nathaniel Lord Britton, in his 1901 “Manual of the Flora of the Northern States and Canada” mentions that Paulownia had “Escaped from cultivation N. Y. and N. J. to D. C. and Ga.” (the similarity in wording between Keller and Brown and Britton is not coincidental, by the way – Keller and Brown cite Britton’s Manual as their source, and also I transcribed the Britton commentary from Brown’s copy of the Manual, that he (Brown) had bought in 1901, fresh off the press – that copy is now at the Academy of Natural Sciences).

And by the 1920s, there were localities where it had fully filled in – such as occurred in northwest Philadelphia: “More than twenty years ago the late Alexander MacElwee collected the Bird Cherry in the northwestern part of Philadelphia, along Gorgas Lane in Germantown. In 1921 there was an opportunity with Mr. MacElwee’s assistance to re-explore this region which is near the head of Wingohocking Creek.  He selected a position along the Philadelphia and Reading Railway just northwest of where Washington Lane Station is now located as probably the spot where he made his collection in 1899.  Here, escaped the processes of “improvement,” are still remnants of natural woodland, now, however, filled up solidly in many places with the Empress Tree and the Gray Birch (a naturalized species here), as well as with an equally weedy growth of the Wild Black Cherry.  Seedlings of the Bird Cherry and young trees up to six or seven feet high may be found scattered through the woodlands for at least a quarter mile.  Near a picturesque, ruined old springhouse in these woods is a thirty-foot tree of the Bird Cherry. The large size and the proximity to the springhouse suggest the possibility of its being a relic of cultivation and the “mother tree” of the Bird Cherries in this vicinity.” (from Bayard Long’s “Naturalized Occurrence of Prunus padus in America”, Rhodora vol. 25, October 1923); I note that this is just northwest of where Meehan’s Nursery was, as one can see in a 1910 map, and that the above cited paper came out just before that nursery closed.

In the 1940 Andorra Hand-book of Trees and Shrubs, it is noted of the Paulownia that “It originally came from China, but has escaped from cultivation, and only when the great panicles of flowers, in May, pick it out of the landscape, do we realize how wide and general is the escape.”

And so, as time rolled on, the Paulownia fell from favor for many in horticulture – Michael Dirr in his Encyclopedia of Trees and Shrubs (2011) calls it a “total loser” (“In the standard frame of reference for shade trees”, at least).

In the 1980s, the Paulownia was still being sold, such as here.  Its extraordinarily rapid growth was still a selling point, as were its brilliant flowers.  And its valuable wood made it a target for criminals, such as the case of the “Fairmount Park chainsaw massacre” that was reported in the Philadelphia Inquirer on the 20th of May, 1983.

The prior year and a half had seen a spate of Paulownia thievery, with rustlers cutting down the trees to sell the wood in Japan to be used for “bridal trousseau chests, jewelry boxes and coffins.”  This happened at least four times, with up to dozens of Paulownias being taken down – and in broad daylight, too.  One arrest was made at 9:30AM on the 9th of May (in 1983).

In the Inquirer report of the above story, William Mifflin, the horticulturalist for Fairmount Park at the time, is quoted as saying that the Paulownia had never been planted intentionally by city landscapers and that the tree was introduced because its seeds were used as packing for porcelain shipped from China and that those seeds were then discarded as the packages were unpacked, thereby disseminating the seeds.

The article also mentions “Probably the most majestic display encircles the Logan Square fountain.”

None of those trees encircling that fountain were ever stolen, so far as I’m aware.  They were also all planted there.

But it wasn’t only Philadelphia that saw this arboreal larceny.  There was also a report in the New York Times, on the 18th of May 1989, of Paulownia thievery – “Several trees were lost on Riverside Drive a few years back, and the population of paulownias at Winterthur … has also been reduced by theft.”

And so there were, and are, a number of problems with growing Paulownias – they grow too fast, they flower too early, their wood proves too tempting for thieves… from its initial high hopes upon its introduction, reality intruded and the Paulownia, the empress tree named for royalty, has been found to be a tree like others, with some qualities that people like, and others that people do not.

Paulownias are still sold – for their colorful flowers and for their extraordinarily rapid growth, and sometimes with the caveat that they can take over a yard.  And they also grow on their own, in vacant lots and along train tracks, up on the roofs of buildings and also in their concrete capped backyards, in all these places and many others, they come up on their own, without help from the hand of man or woman.

You can look out the window of a train going through North Philadelphia, you can look out the window of the El as it goes through Kensington and Frankford, you can look out the window of a car as it goes along Benjamin Franklin Parkway, at Logan Circle – through all these windows, in all these places, you can see the Paulownia; and at Cloverly Park, in Germantown, there is an especially large one, and there is also very large one at the Barnes Arboretum in Merion.  It is a very democratic tree, growing throughout Philadelphia – sometimes put where it is by us, sometimes not, but it is all over the place, either way.  Seemingly sometimes everywhere, the Paulownia grows and does so regardless of whether we put it there, or not.

To read about some other trees, see here:

The saucer magnolia

American Chestnut

American elms

“Penn treaty” elms

The Callery pear

The Caucasian zelkova

London planes and American sycamores

The sophora

Fringe tree

[note: Paulownia trees are just beginning to flower in Philadelphia on the 8th of May 2014; they’re in full bloom throughout the city on the 9th of May 2015 – after a very late and cold winter, too]

Chrysosplenium americanum

Some things last, some things don’t.  A tree like an oak, or a Sophora, or an elm that’s survived Dutch elm disease, these might last for decades, or even into centuries.  A wetland, however, and its concomitant plants, is very often a consistency of change, and this is especially true of the kind of wetland found in the lower areas of Philadelphia – as a stream winds and moves itself through the sand and gravel of the coastal plain, as the ebb and flow of the tides moves the soil here and there, as storms come and go, these wetlands change and shift, perpetually, as they always have.  They can also, especially if they are broad and flat, as many wetlands tend to be, get built upon.  If this happens, if a wetland is gone and built on, it can be difficult if not impossible to reconstruct just where it was, or what it looked like, or what grew there.  But this, sometimes, can be done.

There has been an ongoing effort in Pennsylvania to document the plants of this state, and this effort has led to collections of plants from across PA, and publications based on those collections (including the Plants of Pennsylvania by Ann Rhoads and Tim Block, now in its second edition), and to a database listing these collections – the Pennsylvania Flora Database.  In this database are thousands of plant records for Philadelphia, including one for Chrysosplenium americanum, the American golden saxifrage.

This collection was made by Bayard Long on the 1st of January, 1951, in East Oak Lane, near 2d St and 65th Ave.  Bayard Long was a botanist who worked at the Academy of Natural Sciences for about 50 years, up until the early 1960s, though he never took a paycheck – he was independently wealthy, loved plants, and devoted his time to learning about them, to studying them, to writing about them, and to collecting them.  He was extraordinarily well regarded – Merritt Fernald, botanist at Harvard University and author of the last two editions of Gray’s Manual of Botany (which was the guide to the plants of northeastern North America for most of the 20th century), considered Long a colleague.  Bayard Long’s expertise was well known to anyone who worked on or was interested in the botany of North America at the time, and it still is.

And Bayard Long, on new years day, 1951, went to collect plants in North Philadelphia.

He collected this little plant, Chrysosplenium americanum, and documented it.  This species is a smallish plant, maybe a few inches high, with greenish flowers generally less than a quarter inch across that bloom in spring to early summer – it grows in shady, muddy areas, and would be walked over, if walked by at all, by most people.  And Bayard Long collected it on a winter day, the first winter day of 1951.  And 60 years later, I found out about it, as I looked through the Philadelphia county records of the Pennsylvania Flora Database.

This plant, the American golden saxifrage, is an obligate wetland plant – it is a plant that is not found in drier, upland areas, but is only found in areas regularly inundated with water. This is where it needs to live, and so we know that if it was growing at 2d and 65th, and we do know that it was, then there was a wetland there.  And so I wondered where Bayard Long collected it, where was the wetland that he went to on that cold day in January, over half a century before?  I thought at first it might have been at the Oak Lane Reservoir, between 3d and 5th Streets and between 65th and Chelten Avenues.  Perhaps there had been a wet area associated with the reservoir, a seep perhaps, or a bank or a bit of overflow, where the American golden saxifrage could’ve taken hold.  And, perhaps, 2d Street and 65th Avenue was just the closest street crossing, or where he’d started collecting that day, and so that was what was written down as the locality data.  But Bayard Long was precise, and he was accurate.  If he had collected it at the reservoir, he would have written that he had collected it at the reservoir.  So that wasn’t it.

And so there had to be a wetland very close to or right at 2d and 65th – and there was.  If you look at the G. W. Bromley map of Philadelphia from 1910, you’ll see two streams reaching around, encircling 2d and 65th, and inbetween them, inbetween those streams, would have been a wetland – habitat for this obligate wetland plant.

I’ve never seen this plant in Philadelphia, and so I looked to see if the site might, somehow, still be open, and perhaps Chrysosplenium americanum might, somehow, still be there.  But it’s now covered over.  In the 1950s, Cardinal Dougherty High School was built on top of that site – and after looking at the old maps, the first thing I wondered is what that place looked like before the building was built, when it was open, and the wetland was there.  Well, the school’s website provides.  Cardinal Dougherty history includes a photograph of the groundbreaking for Cardinal Dougherty High School, four and a half years after Bayard Long collected there, and we can see what it looked like then:

Cardinal Dougherty groundbreaking 28th of June 1955

Cardinal Dougherty groundbreaking, 28th of June 1955
Photograph from: http://www.cardinaldougherty.org/

And so the first thing I wondered about, what it looked like, is in part answered.  There was a wooded area there, as we can see from the background, and so the entire area wasn’t always flooded.  This is also evidenced by the people standing there – none of them are wearing heavy boots and so the meadow they’re in most likely wasn’t flooded at least at the time this photograph was taken.  But late June is a bit past the time to get spring floods, and so while this area was not a wet meadow in the summertime, it may well have gotten wet in the earlier springtime.  And even though right then and there it was reasonably dry, we know from the old 1910 map that there were streams running nearby and we know from that old plant collection of Bayard Long’s that there was a wetland there into the early fifties.

And so the second thing I wonder about is if the high school’s basement floods.  Because flowing beneath this school, below the buildings, are streams, as flow beneath many sites in Philadelphia.  Packed away, covered from the daylight, they still flow beneath the city as sewers, or seeping through the ground.  Through pipes and through dirt, the water still runs, it still moves – and when that water moves, those ancient streams will flow, and when they flow, they will flow, and the water will wander where ever it will, even into a Catholic school’s basement, if there are cracks or holes in the walls or the floors, which there may well be.

Cardinal Dougherty High School is now closed.  It’s last class was graduated in 2010.  The buildings still remain, but the school is no more – it no longer is what it once was, and it no longer does what it once did.  This was a wetland sixty years ago, and then it was a school for decades, and it will be something else next.  But things will get left behind as evidence of what was here, or perhaps they won’t.  Things change, but often some things stay.  Even though the wetland where Cardinal Dougherty’s buildings now stand is itself now gone, a memento of it remains, in the Chrysosplenium americanum that Bayard Long collected in 1951.  And so we know what was here, because someone kept it.

There are other wetland plants with histories in Philadelphia – plants such as Micranthemum micranthemoides, Aeschynomene virginica, Zizania aquatica, Sagittaria latifolia (also known under a former name, engelmannia) – all of them tracking historic wetlands that are no longer there, or if they are there, they are changed from how they were in the past.  We can still, sometimes, track back to see how they were, to see where the water flowed above and saturated into the ground, and maybe even to find a picture to see what they looked like, back then.  But like everything, those wetlands are no longer as they were.  However, we can still piece together these little puzzles to think about what they once might have been when they were assembled so differently than they are today.

 

 

(Note: in 1860, Joseph Darrach reported Chrysosplenium americanum as flowering in April in Philadelphia; this was reported in the Proceedings of the Academy of Natural Sciences of Philadelphia)

The Callery pear

There are white flowers blooming all over Philadelphia now.  Some of them belong to the Amelanchier, also called shadbush, or serviceberry.  Some of those white flowers are magnolias.  Some are cherries, and there are others, too, but most of the ones that you’ll see at around this time are the blooms of the Callery pear (Pyrus calleryana), with their copious flush of white and their peculiar acrid smell.

If you look closely at them, one thing that you’ll notice is that nearly every set of flowers is accompanied by its own set of leaves.  Look closely, and poke around in the inflorescence (a cluster of flowers, that is) and you’ll see that each individual flower is connected to a little stem, in a somewhat spiral arrangement, winding down the axis, or winding up it, depending on which direction you go.  Each one of those flowers is accompanied by a little tiny leaf, or a leaf scar to show where a leaf once was – each one repeats the other, in modular form, winding around the stem, up and down the line.  Except all the way down the line.  At the lowermost position on the inflorescence, the one closest to main part of the tree, there is almost always a set of a leaves, a little tuft of green, instead of a flower.

Why are those leaves there and what are they doing?  It could be that they provide a local food source for those flowers, early on in their development – those photosynthesizing leaves harvesting energy from the sun and gathering carbon dioxide from the atmosphere, twisting the two into sugar, and shipping that sugar right to the nearby flowers, flowers that need energy to grow and to breed, these leaves open up when the flowers do, since they are in there in the bud with them, and they pop out along with the flowers, and would provide sugars just a short distance away, and at the right time. It’s expensive to ship sugar around a tree, as it takes energy to move things, and so doing it locally, right next to the inflorescence, instead of having the leaves come up some distance away and transporting the food that some distance, it would just simply be more efficient to do it closeby.  By having the leaves right next to the flowers, the source right next to the sink, this would save precious time and energy, always a valuable set of resources, but resources even more valuable in the spring, just after the trees have woken up and are drawing down their stored energy supplies, supplies that they packed away last year and have only in limited amounts.  And by having those leaves right there in the bud, good timing is assured – no need to wait for the leaves farther away to open up (which they will later) when you have your own right there in the package with you.  And so those little tufts of leaves at the bases of the inflorescences are quite likely feeding their neighboring buds and blooms.

And also, those leaves could be beneficial to the tree by drawing up water, pulling it towards the flowers, who need to drink, too.  The way that water moves up a tree is, basically, that the water evaporates from the leaves through little holes, called stomata; this evaporation draws the water up through tiny pipes, called, collectively, xylem, in a somewhat similar way to how water goes up through a straw when you draw on it as it sits in your waterglass.  In fact, you can see how this works by taking a drinking straw and putting it entirely underwater so it fills with water, then taking a piece of a cotton ball and jamming it tightly into one end of the straw and then taking the entire contraption up and out into the air.  Then, place it, cottonball end up, into a glass with more water in it, but this time with water that has a little bit of food coloring in it.  Then wait.  Or just come back later.  Either way, after a while, you’ll see the dyed water migrating up through the straw, ultimately dying the cotton ball whatever color you have chosen from your pack of food dye, that you used to stain the water in which the straw is sitting.  This illustrates, essentially, how water moves through a tree – the water evaporates from the leaf (in our experiment, that’s analogized by the cotton ball), which pulls it through the xylem (the straw, in our table top set up), which in turn pulls the water out of the soil (which is represented by the glass that holds the tinted water).  And so, if leaves are situated next to the flowers of the inflorescence, which they are in the case of the Callery pear, then they would be drawing up water, water that could be shared with the petals and the sepals, the anthers and the stigmata, the parts that are the hopes and dreams for the next generation of trees.

But whyever they are there, the fact remains that those leaves are there, and they are here and there throughout Philadelphia, along streets and in parks, pretty much in every neighborhood.

But how did they, and their accompanying trees, get here to Philadelphia?  The Callery pear tree is originally from east Asia, and since trees can’t walk, and nor can they swim, they had to have had some help in getting to North America, and their main agent of dispersal, the organism who got the seeds of the Callery pear to the new world, was Frank Meyer.

Frank Meyer was a Dutchman, and he was also a botanist.  Towards the end of the 19th century, Meyer worked as the head gardener in the experimental garden at the Amsterdam Botanical Garden, but this wasn’t enough to satisfy his yearnings for travel and his love of plants, and so he came to America in 1901, where he soon began to work for the US Department of Agriculture as a plant explorer.  One of his missions, towards the end of his career, was to collect the Callery pear.

Meyer wasn’t the discoverer of the Callery pear – that credit goes to the mid-19th century French missionary, Joseph Callery.  Nor did Meyer introduce it into cultivation – that credit goes to E. H. Wilson of the Arnold Arboretum.  However, what Meyer did was to send back bags of seeds, in 1917, from China, of the Callery pear, so that this plant could be introduced into cultivation by the USDA, thereby leading to its widespread dissemination.  Why was he told to collect and send back those seeds?  Well, at that time, the US pear industry was being decimated by fire blight, a bacterial disease, and it had been found that the Callery pear was resistant to this disease, and so could be used in breeding programs and for rootstock.  This program was quite successful, and when it was also found that the Callery pear can live under some difficult conditions, like a fair bit of drought, the Callery pear became commonly used in orchard production.  (fire blight is still a problem in pear orchards, by the way: http://www.ars.usda.gov/is/pr/2015/150130.htm )

And then, some decades after that initial delivery of seeds by Frank Meyer, USDA researchers in the 1950s noted that the Callery pear also had nice flowers and this, combined with its resistance to environmental stress, meant that the Callery pear was realized to be a tough and attractive street tree, and it rapidly became extremely popular, which is why we see it all over Philadelphia.  But it most likely wasn’t just the tree itself that led it to be so widely planted.  The timing of this work was probably key, also, to the widespread spread of the Callery pear.

These trees, the Callery pears, came in and replaced, in part, the American elm – the American elm was the premier tree of parks and streets and so many other landscapes throughout the US, up until the midpart of the 20th century.  Its vaselike structure, with branches growing up and out, made for tremendous arboreal arches that gracefully covered many streets in small towns, and big cities, and other places, too, until the Dutch elm disease knocked out this elm, and many others like it, taking it out of commission as the street tree of choice, requiring a replacement, many replacements actually, to fill the elm’s ample metaphorical shoes.  The Callery pear was one of those trees, and it became extremely popular starting in the 1960s as a tree for the street habitat, a niche that had been opened up by the Dutch elm disease.

If you see a row of Callery pears, what you’ll often notice (I know that I do) is that they frequently will all have a spraylike branching pattern, where the trunk will grow nice and straight up until about 4 or 5 or 6 feet or so, and then there will be a division of that upright axis, where branches will grow angled outwards, kind of like an upside down broom.  You might think that this is very thoughtful of the tree, to make such an eyepleasing design at about eye level, reminiscent of the form of the American elm.  However, plants don’t think, or at least I don’t think they do, and this shapely pattern is due to the hands of man.

If you cut the top off a tree, it generally will not die.  It will however, grow quite differently than it would if it had not been decapitated.  Branches that were formerly suppressed by hormonal signals sent out from that top leading growing tip can now grow, and they do – and sometimes all at once.   This is what happens with the Callery pear.  If the top of the tree is removed, you then get a spray like pattern to the branches that grow to replace that lost top.

And so, if you walk down a street, for example, 19th Street alongside the Academy of Natural Sciences, just below Logan Circle, you’ll see that at about shoulder height, the branches of the Callery pears begin to spread, and you’ll know that at some point in time, someone walked among those trees, cutting them at an easy height to reach, about shoulder height, to make those Callery pear branches angle like they do now, an angle reminiscent of an American elm.

People don’t plant Callery pears quite so often anymore – their branches tend to break, and there are concerns about its invasiveness.  This tree, which is one of the few major introductions of the 20th century to our street tree flora has had its time in the sun.  It was introduced, it had a population boom, and now we will see where it will go in the future, what part it will take among the street trees of Philadelphia and elsewhere.

Callery pear inflorescence, NYC Photo courtesy Joseph Wendler

Callery pear inflorescence, 27th of March 2012, NYC; Photo courtesy Joseph Wendler

Note: the Callery pears in Philadelphia are just now hitting there full bloom on the 13th of April 2014, and they are in fully bloom in NYC, too:

Manhattan-20140418-Wendler_Callery pear

Callery pear in Manhattan, 18th of April 2014; Photo courtesy Joseph Wendler

London Planes and American Sycamores

All around Philadelphia, and in many other cities as well, the streets are lined with London Plane trees.  These trees, with their trunks of exfoliating bark making them look to be covered in military camouflage, are recognizable from a hundred yards away.  Or so I used to think, until I looked closely at the confusion and complexity that surrounds this seemingly simple and so common tree.

The London Plane is of hybrid origin – it is the offspring of two different species, the American sycamore (Platanus occidentalis) and the Oriental plane (Platanus orientalis), and it is a tree that did not exist prior to European colonization of the new world.  Before then, American sycamores and Oriental planes were kept separate by an ocean (the Atlantic if you’re going east from the US, or the Pacific if you want to go all the way around the other way), and they didn’t come together until the 17th century, when John Tradescant the Younger, a botanist and gardener (as was his father – John Tradescant the Elder, that is), came to the colonies in the early part of that century and in 1636 took the American sycamore to England.  There were also Oriental planes in England at that time (they’re originally from the more eastern parts of Europe), however though the geographic distances that had previously kept the orientalis and occidentalis separate were gone, still for some time after 1636 age differences would have maintained that separation, as it takes time for trees to grow, and to make flowers, and to shed pollen, and to make new seeds for new plants.  And so for some time these different plants, though now together after having been so long separated, would still have remained distinct from one another.

By 1700, though, east had met west.  We know this because in that year Leonard Plukenet, yet another English botanist, described an intermediate between the Platanus species that were already known (i.e., orientalis and occidentalis), and so from this we can infer that the London plane had arisen by then, an intermediate that looked like what it was, a hybrid cross of two morphologically distinct species.  How, when, where and why this happened, we do not know exactly, except that it was in England in the latter part of the 17th century (the latter part because it would have had to have been long enough after 1636 to have allowed for the seeds Tradescant brought back to have grown into seed bearing trees themselves).  Other than that, we can’t say with more detail, with any confidence at least, when this hybridization event occurred.

It also isn’t clear when this hybrid, the London plane, came to the US (or one could say semi came back to the US, since half its genetics is from the new world) and to understand why, you have to understand the plants.

London planes look quite a bit like their parent species, as you might expect, since that’s how genetics works (like begets like), and so it can be difficult to differentiate them.  This is something I learned recently – I had thought for years it was easy to tell them apart, to differentiate the London plane from the American sycamore.  But, as with so many things, I realized that the closer I looked, the more complicated it became.

There are, broadly speaking, four main characters that are useful for telling these trees apart, the London plane and the American sycamore.  Two of those characters involve the bark.  On London planes, the military camouflage appearance mentioned above, in the first paragraph, is found up and down the trunk of the tree – on American sycamores, the bark is thick and rough up most of the main trunk of the tree, only exfoliating (peeling away) further up.  And American sycamores generally have a white, and commonly bone-white, tone to the underbark that is exposed from the peeling away of the outer bark layers, while the London plane’s underbark will have a yellow or green tinge (or sometimes even a salmon orange color, as is found on a tree in Pastorius Park in Germantown, here in Philadelphia).

The leaves also differ – the leaves of both trees are lobed, and in the London plane, the center lobe is longer that it is wide, whereas the sycamore’s is generally wider than it is long.  A final character separates the two – the flowers (and then later, of course, the fruits) are borne on dangling peduncles (what we might call “stems” in normal English), and in American sycamores these are borne singly, while on the London plane they hang in twos and threes.

Something else also differentiates these trees – their habitats.  If you’re in the floodplain of a river or creek and you see a tree that looks like an American sycamore, it probably is.  If you’re on a city street, and you see a tree that looks like a London plane, it most likely is.  London planes are phenomenally sturdy street trees – they’re called “London planes” because they are and were so common throughout London, and while yes this is due to their attractiveness, it’s also because they were able to grow in the soot filled air of 19th century cities, and so became exceedingly popular, especially in London with its thick industrial era atmosphere.  Since its introduction to urban life, this tree has had times of peak interest, and times of reduced interest, as is noted in William Flemer III’s article “Island and Median-Strip Planting”, in Arnoldia [vol. 44(4), pp, 14-28 (Fall 1984)]: “The London plane tree has gone through several cycles of popularity and disapproval.  Many years ago a few nurserymen grew the trees from seed that produced great variation in habit of growth and disease resistance and this may be one cause for the disapproval.  Another may be the plane tree’s vulnerability to canker stain disease, a serious condition spread by pruning tools or other mechanical means.  The severity of the disease once led the city of Philadelphia to enact ordinances that prohibited planting the tree.”  But, I should add, even though the London plane has had its ups and downs in popularity, it still, generally, will do better in an urban environment than the American sycamore will.  This habitat differentiation is noticeable if you go to the Powell house on 5th Street in downtown Philadelphia – there is a London plane planted right next to an American sycamore.  The London plane is doing quite well, happy as can be – the sycamore, much less so.

Another habitat in which one seems to often encounter American sycamores is graveyards.  There’s an enormous sycamore in Greenwood Cemetery, in Frankford, and another one in the churchyard/graveyard of St. James the Lesser, which is up near Laurel Hill Cemetery – there’s also some planted in the Palmer Burial Ground in Fishtown, and quite a few planted in West Laurel Hill, just over the city’s border, in Bala Cynwyd; there’s also an enormous one in the Germantown Friends burial ground that you can see easily and clearly from Germantown Ave, if you’re standing just a bit west of Coulter St.; there’s also one in the Friends Meeting House yard at 4th and Arch – there used to be a cemetery there, too.  [there’s also a very large American sycamore at the Germantown Cricket Club, next to the parking lot]  The symbolism of this makes sense, planting sycamores in Christian cemeteries.  In the gospels, e.g., in Luke 19, when Jesus is going through Jericho, Zacheus, the chief tax collector in town, climbs what is called a sycamore to see Jesus as he is walking by – Jesus sees Zacheus up in the tree and calls to him, and Zacheus then “received him joyously”, as it says in the King James Version.  Now, this tree from the bible is said to have most likely been a sycamore fig, and certainly was not the sycamore that we have in the US, but the symbolism, one might imagine, would still work and would be effective, because in a graveyard in which the dead await the return of the messiah, one would want a tree for them to climb up on Jesus’s return, so they can see him, and perhaps more importantly, be seen by him.

American sycamores can also grow to enormous size – in the early part of the 20th century, the American Genetic Association put out a call for photos of and associated data for the largest trees in America.  They published results of this in 1919, in the Journal of Heredity, and the largest tree by far was an American sycamore in Worthington, Indiana – it was 42 1/4 feet in circumference.  London planes can grow quite large, but I’m not aware of any that come close to that kind of size.

However, even though there are a number of differences between these plants, it can still be difficult to tell them apart.  Why?  Because even though the London plane is of hybrid origin, it still makes viable seeds, and those seeds are enormously variable, because they contain the genetics of both the parent species, in every combination available.  Also, the London plane can back cross with its parent species, thereby further mixing up the characters.  And so, many of the trees I see in Philadelphia that I once would have easily called “London plane”, I’ve come to notice often have a mix of the characters with those of American sycamore – and so separating them isn’t so easy.

This all helps to make it difficult to figure out when the London plane came to the US – if we find it difficult now to separate them, it’s not like it was any easier in previous decades or centuries, and trees identified as Oriental planes and American sycamores in old documents quite easily could have been misidentified London planes.  William Hamilton, owner of the Woodlands and an avid plant collector who sent numerous plants over from England in the 1780s, when he wrote to his gardener in 1785, he mentioned he had sent over 12 plants of “platanus orientalis”.  This may well have been London plane trees.  Or it might not have been.  We will most likely never know, because absent the plant itself, the name alone just doesn’t tell us for sure what it is.  This is the case for listings in numerous nursery catalogs (including Meehan’s) – Platanus orientalis, for example, may be listed for sale, but we just can’t be sure if that was what they were selling, and so tracking the movement of the London plane is difficult, if not impossible, to do.  An example of this confusion can be found in an article in the magazine “Park and Cemetery Landscape Gardening” from 1916, where, in an article enumerating “Trees for Adverse City Conditions” includes “Platanus orientalis (The Oriental or London Plane)”

And even the plant’s name is confused and confusing.  The latin name most commonly used for the London plane is Platanus x acerifolia (the “x” indicates its hybrid status), however, another valid name is Platanus x hybrida – this confusion arises because we don’t know which name, hybrida or acerifolia, came first, we don’t know which was assigned before the other.  This is important to botanical taxonomists (i.e., people who name plants) because sometimes a plant is named more than once; for example if someone thinks they’ve discovered a new species, and they describe it and name it, but it turns out that they just didn’t know that someone else had named it before, well that first name that was applied previously is the one that is supposed to be used, and not the later one. This often simplifies things because the choice is based simply and solely on date of publication of the name of the species.  However, it’s not always easy to figure that out, and this is one of those cases – while we know that both of these names for the London plane were assigned in 1805 (hybrida by Félix Brotero, a Portuguese botanist, and acerifolia by Carl Willdenow, a botanist in Berin), we don’t know exactly when within that year these names were used, and so priority is confused, and so are we.

And there are further questions of nomenclature here – due to the backcrossing with the parent species, and because plants grown from seeds that are progeny of a hybrid are not, strictly speaking, hybrids themselves, it furthermore becomes complicated as to whether or not many of the London planes we see should truly be called hybrids, and therefore include that little “x” in there.

The confusion doesn’t end there.  Due to that Brotero name, “hybrida“, one might think that the hybrid origin of the London plane was clear and understood early on, or at least by the earliest part of the 19th century.  But even this wasn’t clarified until much later, in 1919, when Augustine Henry and Margaret Flood thoughtfully marshaled the evidence – intermediate morphology that is between the two parent species, highly variable seeds that show traits of both parent species in various combinations – in a paper in the Proceedings of the Irish Royal Academy that clearly indicate that yes, the London plane is a hybrid of the trees from two continents.  So perhaps the confusion does end there, at least for that one question, and at least for now.

To read about the importance of cemeteries to urban planning, see here:

https://cemeterylandmanagement.wordpress.com/

To read about some other local Platanus, see here:

https://growinghistory.wordpress.com/2012/04/10/the-trees-of-monument-cemetery/

https://growinghistory.wordpress.com/2012/03/20/the-yard-of-the-wagner-free-institute/

To read about some other trees, see here:

The saucer magnolia

American Chestnut

American elms

“Penn treaty” elms

The Callery pear

The Caucasian zelkova

Paulownia tomentosa, the empress tree

The sophora

Fringe tree

A painting of planes by Van gogh

A painting of planes by Van Gogh

Some history of historic plants

One of the goals of Growing History is to propagate plants from historic sites, and to then share those plants among places with historic, cultural or horticultural significance, or just simply with places and people who love plants and history.

The idea of propagating specific plants of historic significance, however, isn’t new.  In the 1917 catalog for Meehan’s Nursery, there is an advertisement for “Historical Elms”, that were “Not seedlings, but scions actually cut from the historical trees …” and the listing in the catalog goes on to say that “This is the only lot of similar plants known to exist in this country.”  (This catalog and others like it are at the McLean Library of the Pennsylvania Horticultural Society, in Philadelphia)

There were 37 different such elms offered in the 1917 catalog, and they were mostly from England, from sites associated with the upper class such as high end schools (e.g, Oxford, Harrow, Eton) and other kinds of places like that, including Windsor Castle and Westminster Palace.

But historical elms weren’t just for anglophiles – the nursery also had Penn Treaty elms, that is, descendants from the Penn Treaty elm (it was an American elm), under which William Penn engendered his treaty with the Lenape at what is now Penn Treaty Park, by the Delaware River in Philadelphia.  That tree is pictured here (in Benjamin West’s Penn’s Treaty with the Indians, painted 1791-1792; image from the website of the Pennsylvania Academy of Fine Arts: http://www.pafa.org/Museum/The-Collection-Greenfield-American-Art-Resource/Tour-the-Collection/Category/Collection-Detail/985/mkey–2609/):

To give a bit more background on the Penn Treaty elm, and a bit of foreground, too, we can turn to Edward Embree Wildman’s book “Penn’s Woods: 1682 – 1932”.  Published in 1933, this book attempted to document all the trees in the area that were alive at the time of William Penn’s arrival in 1682 and were still living at time of the 250th anniversary of that arrival.  [Note: as of 1979, there were only two “Penn trees” remaining in Philadelphia county, according to an article in the Ocala Star-Banner published on the 11th of June 1979 (there were 24 documented in 1932)]  And the Penn Treaty elm was, to Wildman’s view, “Pennsylvania’s Most Historic Tree”, and on pages 128-129 he covers what it was, where it was, and where it went:

“Penn Treaty Elm at Shackamaxon (now Kensington)

Preserved for us on canvas by Benjamin West in his famous painting, “Penn’s Treaty With the Indians,” now hanging in Independence Hall.  When blown down by a storm on March 3, 1810, its circumference was twenty-four feet, its main branch one hundred fifty feet in length and its ring count showed its age to be 283 years.  Dr. Benjamin Rush had an armchair made from its wood.  General Simcoe, during the Revolution, when firewood was scarce, placed a guard of British soldiers around the tree to protect it from the axe.

Scions of the Great Treaty Elm

The only recorded scion of this famous tree was moved about a century ago to the Oliver Estate at Bay Ridge, N. Y.  In 1887 this tree was again moved to the present Oliver estate near Wilkes-Barre, where it stands opposite the Town Chapel at Oliver’s Mills

Scions of the Second Generation
(Grandchildren on the Great Treaty Elm)

1. North of College Hall on the campus of the University of Pennsylvania, planted on April 10, 1896, by Governor Hastings.

2. South of Founder’s Hall on the campus at Haverford College.

3. On the grounds of the Pennsylvania Hospital, Eighth and Spruce Streets, Philadelphia

4. Beside Bacon Cottage at Westtown School, four miles east of West Chester.  Planted by Dr. Wills

5. In front of Johnson Library, Camden, N. J. This seedling was carried in her apron by a nurse from Shackamaxon to Elizabeth Cooper, who with her two brothers built and gave Cooper Hospital to the city of Camden.

Scions of the Third Generation
(Great Grandchildren of the Great Treaty Elm)

Developed from cuttings taken from the grandson on the Haverford campus, we may now see on the same campus, about two hundred fifty feet southeast of Roberts Hall, seven great grandsons of the Penn Treaty Tree, presented by an alumnus in 1916.  Thus followed an old English custom of planting seven trees of the same species in a group.”

Katharine Stanley Nicholson also discusses these trees, in her 1922 book Historic American Trees:

“Descendants of the Penn Treaty Elm

General Oliver’s Tree

When the land where the Treaty Elm had stood came into the possession of General Paul A. Oliver’s ancestors, a shoot was discovered springing up from the old tree’s roots.  This was transplanted to Bay Ridge, N.Y., where it flourished until after fifty years it had almost reached the size of the parent tree. Then the General removed it to his home at Wilkes-Barre Penn., where it has continued to thrive.

On Arbor Day, April 10, 1896, a shoot from General Oliver’s tree was planted on the campus of the University of Pennsylvania Philadelphia, by Governor Hastings of that State, in honor of William Penn, first Governor of the Commonwealth.  The tiny sapling grew into a healthy tree which has rounded out its first quarter century. It is one of the youngest of the Great Elm’s descendants.

Another scion of the old tree stands on the grounds of the Pennsylvania Hospital Philadelphia and yet another in the yard of the Friends’ Meeting, in Twelfth Street, in the same city, silent witnesses to the memory of the Great Treaty, which Voltaire described as the only agreement “between the Christians and the Indians that was never sworn to and never broke.”

As Robert Piper, President of the Pennsylvania Forestry Association notes, there is solid evidence that the tree at Penn was planted for that organization –

Penn Treaty Elm Scion Plaque_photo by Robert Piper

Image courtesy the Pennsylvania Forestry Association.  Photo by Robb Piper, PFA President 2014-2015

(NB: the 1896 planting mentioned above was mentioned in the March 23, 1896 New York Times; the piece reads: “A Cion of  the Penn Treaty Elm/ From the Philadelphia Times/ Gen. Paul A. Oliver of Laurel Run has shipped an elm tree to Philadelphia, where it will be planted on Arbor Day, April 10, by Gov. Hastings.  The Governor will plant the tree in honor of the first Governor of this Commonwealth, William Penn, on the campus of the University of Pennsylvania.  The tree is a branch taken from a tree grown in the log chapel yard at Oliver’s Mills, in which Gen. Oliver takes much pride, as it is fifty-six years old and was grown from a branch of the original Penn treaty elm.”; there is also, according to this: https://www.ursinus.edu/offices/sustainability/sustainability-on-campus/grounds-and-trees/penn-treaty-elm/ an offspring of the Haverford treaty elm, at Ursinus College – “Our tree was planted in 1976-77 from a seedling from Haverford College’s grandchild tree.  The tree on campus, which is located by BPS, near the power plant, the knitting woman statue and Corson Hall, is a fourth generation tree from the original Penn Treaty Tree.”)

 

 

And so, if we follow Wildman’s and Nicholson’s histories, the Treaty elms that were sold in Meehan’s catalog had first made a detour to Bay Ridge, and ultimately ended up for sale back home, here in Philadelphia.

These Penn Treaty elms were $8 each for the 1 inchers and $5 a piece for the half inchers. (The elms from England were 10 each, by the way).

We don’t know what became of these trees, nor how many were sold and to whom they were sold – as of now, all we have is this record of the listings from Meehan’s Nursery catalogs (there’s a similar listing in the 1916 catalog), a record of an early 20th century interest in historic plants, and an attempt to make some commercial value from that.

Meehan’s Nursery itself is now a part of history.  The nursery was in two sites, one in Dresher, PA and one in Germantown (in Philadelphia).  The Germantown nursery had its northwestern boundary at what is now East Vernon Road, and its southwestern on Chew Avenue; and as is mentioned in Meehan’s 1881 nursery catalog (which is accessioned in the collections at the McLean Library), it was of substantial size: “We have forty acre in nurseries in the city of Philadelphia”, they write.  If you walk along East Vernon Rd today, and you walk northeast from Chew and you see rows of Cedrelas, tall trees with enormous panicles of white flowers in June, planted along the sidewalk, you are on the street where the offices of Meehan’s Nursery were, a hundred years ago and more.  (Note that Cedrela was here in the 19th century, as is indicated in John Harshberger’s 1899 The Botanists of Philadelphia and their Work: “Here, too, is a fine specimen of Cedrela Sinensis, nearly thirty feet high.”)

The nursery was founded in 1854 by Thomas Meehan, who is quite a historical figure himself – in addition to developing his enormously successful eponymous nursery, he was also a founding member of the Philadelphia Botanical Club, a Philadelphia City Councilman, an avid developer of city parks throughout Philadelphia, the rediscoverer of the pink dogwood, and a correspondent of Charles Darwin, Asa Gray, and other luminaries of the 19th century.  And prior to his arrival in the US in 1848, he’d led an interesting life as well; as Edwin C. Jellett writes in his 1914 book Germantown Gardens and Gardeners, “Thomas Meehan was a Chartist, therefore a marked man, and finding it impossible to hold a position in England, he decided to emigrate to Pennsylvania”.  Thomas Meehan died in 1901 and the nursery was then run by other members of his family.  It closed in the 1920s, and shortly thereafter a housing development was built where the nursery once stood.

Today, if you walk up E. Phil Ellena Street or E. Hortter Street, from Chew Avenue, under the oaks that were planted when the development was built, you are on the grounds of what was once one of the major nurseries in eastern North America.

The oak trees that are now there can be seen, as youngsters, in this picture:

View looking along Hortter Street in 1927, after the development that replaced Meehan’s Nursery was developed. http://www.phillyhistory.org/PhotoArchive/Detail.aspx?assetId=9508

And Meehan’s is linked further and deeper into horticultural history.  Prior to his many accomplishments, at the start of his career, Thomas Meehan was a gardener at Bartram’s Garden.  In the late 1840s, soon after he came to the US from England, he worked as a gardener there. This relationship comes around again in the 1890s, after Meehan had made his fortune as a nurseryman and become a politically influential member of the Philadelphia community, when he fronted the movement to keep Bartram’s Garden as a garden, thereby preventing it from becoming built upon by developers.

And so, nothing is new.  Today, we propagate historic plants, and we find that Meehan’s Nursery did that nearly a hundred years ago.  Today, those of us who are interested in gardens and natural history spend time with others who feel the same, and we want to preserve the historic sites that are key to these interests.  And, as we do today, Thomas Meehan linked sites and institutions in the 19th century and worked to preserve them.

And so, nothing is new.

For more about pre-colonial trees (“Penn trees”), see here:

Hemlocks (along the Wissahickon)

American chestnut (and others)