No Ill Nature: The Surprising History and Science of Poison Ivy and Its Relatives

To read the new article about poison ivy by Jane Boyd and Joe Rucker in the Chemical Heritage magazine, see here:



Just to the north of where the Frankford El ends, there is a set of cemeteries, and a park that nearly entirely circles one of them.  Those cemeteries, Cedar Hill, North Cedar Hill, and Mt. Carmel, have been there since this was a rural area just outside of Frankford’s urban core.  And the park, Wissinoming Park, while not quite as old as those cemeteries, has history that does reach a bit further back.

The site of Wissinoming Park was originally the estate of Robert Cornelius, a chemist and an early photographer who began his work in the latest part of the 1830s and took one of the earliest photographs, ever, of a living human.  Mr. Cornelius was a very wealthy man, and in the 1850s he wanted an estate in one of the finest parts of Philadelphia, and he situated it just to the north of Frankford, to enjoy the space and the rural setting he found there.  And it remains open to this day – a swath of green and trees that has been a neighborhood treasure for well over a century.

In an undated piece by Thomas Creighton, from the archives of the Historical Society of Frankford (and thanks to Susan Couvreur for finding this and bringing it to my attention), we find the following:

“One of the most pleasing and attractive of the new parks of Philadelphia is Cornelius Park, situated a short distance above Frankford, and on the western outskirts of Wissinoming it will in due course of time be greatly appreciated.  There are fine forest trees, open glades, and a lake that always adds to the beauty of the landscape”

In this article, they mention that the park had just opened, and that “There some 34 members of the society gathered on Saturday afternoon, October 14…” and:

“Mr. Robert T. Corson, Esq., read a very complete history of the ground comprising the estate, from the time that it was a part of the glebe lands of Oxford church to the present time, of its purchase by the city for a public park.”

This suggests that this article was published (by the Historical Society of Frankford) in 1911 (the 14th of October fell on a Saturday in 1911; also you’ll note that the park is not on the 1910 map here, but it is on the 1929 map there), or perhaps 1912 (since there might have been a delay in publication to the following year after the visit mentioned above).

The paper goes on to say:

“In May 5, 1850, Lawndale, the estate of Edward Lukens and wife, was purchased by Mr. Cornelius for $18,500.  Mr. Cornelius was a great lover of trees and it is stated that he planted about 4000 trees on the place.  There are some very old walnut trees still standing, one large one that stood before the mansion is dead and will soon have to be taken down.  The mansion was torn down recently owing to its neglected condition.”

This mention of walnuts is interesting to me because there are a few black walnuts in Mt. Carmel Cemetery, the cemetery at the northeast corner of Cheltenham and Frankford Avenues, whose land used to be a part of the Cornelius Estate.  In the late 19th century, a portion of the estate was cut off to become Mt. Carmel cemetery, and as an interesting aside, the owner of the first matzah factory in Philadelphia, Werner David Amram, is buried there.  He also was my great great grandfather.

[Note: to read more about a couple other nearby cemeteries, see here]

But back to the trees…

I’d assumed that those black walnut trees at Mt. Carmel had simply seeded in on their own and that no one had removed them; that is, that they’d just weeded their way into the landscape, since it seemed a bit odd to me to plant black walnuts in a cemetery, given that these plants shed nuts prolifically, nuts that are time consuming to pick up from the ground and discard.

However, on a visit to the Frankford Arsenal this past July (which was kindly organized by Cynthy and John Buffington, by the way), I saw that there is an enormous black walnut near the reflecting pool in the southwest corner there, and there are also two smaller ones (black walnut trees, that is) arranged at the far corner of the pool from it.  I was surprised to see them there (for a similar reason that I was surprised to see the ones at Mt. Carmel), and based on the placement of the larger tree (relative to the pool, and also relative to those other two walnuts also near the pool), I’m quite sure it was planted there, and that those two smaller ones are, too.  Since those black walnuts at the Arsenal are pretty clearly planted, and since it is noted that walnuts (which may well have been black walnuts) were noted to have been planted on the Cornelius estate, I have had to reappraise my thoughts on black walnuts being planted (and not seeding in on their own), in landscapes in Frankford (and most likely elsewhere), such as Mt. Carmel Cemetery.

But back to the park…

In the late 19th century, the estate had an open, park like aspect to it, much as it does today – this I saw in photographs from the archives of the Historical Society of Frankford, access to which was kindly granted to me by Susan Couvreur and Diane Sadler.

And if we look at old maps, we see that there were two streams running through the estate – one ran in a roughly southwesterly direction, the other went roughly southeast.  The two joined in the southern part of the estate, and then crossed what is now Cheltenham Ave (but at the time was Dark Run Rd).  The southwest running creek has since been covered over, but there is now a long low area running above where that creek once ran – I talked to some people at the park and they call it “the creek”.  It dries out when the rain doesn’t come, so it isn’t totally a creek, but when the rain comes, the creek fills up, and so it does have a flow at times, and so colloquially calling it a creek makes sense to me.

The southeasterly running stream started just across Frankford Ave, in the eastern part of the property owned by North Cedar Hill Cemetery, but in an area that is, so far as I’m aware, unburied with bodies.  It’s just a bit southwest of what might be the oldest community garden in Philadelphia, which is in turn just a bit southwest of Benner St, on the north side of Frankford Ave.

I’ve talked to people, such as Robert Penn, who’ve lived in the area in decades past, and they’ve told me that there used to be a spring there, where that creek began, just north of Frankford Ave, just west of Comly, where people would go to get drinking water. But it was closed down in the 1950s or so, due to concerns about its cleanliness.

There were many springs in the parks of Philadelphia, in former times, such as the one described in the “Conchologists’ Exchange“, where John Ford (Philadelphia, PA) describes a locality in West Fairmount Park, in 1887:

“On the eastern embankment of the Philadelphia and Reading Railroad about 200 yards below Belmont Landing, the remains of an old spring house may he seen with the water still bubbling up among its ruins, across which rests the trunk of a fast decaying tulip poplar.”

The stream that came from that spring in Wissinoming was dammed up, in Cornelius’s time and on Cornelius’s property, to make a large pond – the area where that impoundment was is now covered by concrete and is part and parcel of the park that is there today, and kids now play street hockey there, above where a pond once was.  There is a drainage that still runs underground there, with an entranceway to it that you can see at the southwest part of the cemented play area, and there is a little bridge that stands to mark where a stream once was.

It was not unpopular, in the late 19th and early 20th century, to install water features in parks, as we see from the 1901 “Twenty-Ninth Annual Report of the Board of Directors of the Zoological Society of Philadelphia” [or “the Philadelphia Zoo”, as it is more commonly called today]:

“Through the interest of a generous patron of the Gardens, means were provided for converting the upper portion of the stream in rear of the deer park, into a pond for otter, which has proved to be one of the most attractive features of the collection. At the lower end of the same stream, adjoining the beaver, another inclosure has been made for wood ducks.”

But these water features don’t last forever – things come and things go, like water under a bridge.

There was also, I’ve been told, a farm near there, as late as the 1950s, just north of North Cedar Hill Cemetery, and that it was owned by the same Brous family for whom Brous Ave is named.  But I haven’t found out more about that, yet.

Those creeks that ran through Wissinoming Park were tributaries of Little Tacony Creek – Wissinoming Creek ran a bit north and east of the park, and flowed directly into the Delaware.  That waterway, Wissinoming Creek, like so many others in Philadelphia, has long since been covered over and hasn’t seen the light of day in decades, but its legacy still remains, both in the name of the park nearby (Wissinoming Park, that is), and also in the open park like spaces along Devereaux St., and Hegerman St., and Vandike St – streets that were set above where the creek once ran.

In 1999, there were houses on those lots – but they’d been built, in the 1920s, on top of the ash and cinder filled stream bed of the Wissinoming Creek, and that light debris didn’t support the houses well enough, and by the end of the 20th century they were declared by the city to be “in imminent danger of collapse.” – and so they are now open spaces, grassy and green, and dotted a bit with trees, telling of what runs beneath them.

Back in the 1920s, when this area was being heavily developed, it had a very different aspect to what it has now, as you might expect, but in ways that might be surprising – for example, there was open wetland, and pretty good quality wetland, too, along what is now Cheltenham Ave, in the area near Wissinoming Park.

We know this because, at the Academy of Natural Sciences, in their collection of dried and pressed plants (called an “herbarium“), there is a collection of Sparganium americanum, collected by R. R. Dreisbach on the 12th of July in 1922.  He noted the habitat location as “Marshes / Dark Run Rd.  Frankford, Phila Co.”

Sparganium americanum, or American bur reed as it is more commonly known if it is known at all, is an obligate wetland plant; that is, it needs saturated soils to live – and so we know that there were open wetlands at the site where it was collected.  Also, while this bur reed isn’t the most sensitive of plants, it does need somewhat clean water and this indicates that the water was not overly polluted at the time it was collected. [for example, in  Small et al’s 1994 paper in Restoration Ecology, “A Macrophyte-Based Rapid Biosurvey of Stream Water Quality: Restoration at the Watershed Scale”, they report Sparganium americanum from nearly 27% of the high quality streams they surveyed in the Chesapeake Bay watershed, yet not at all from their low quality stream sites]

We have to use old maps to suss out the location indicated by Dreisbach for his bur reed collection, to see where Dark Run Rd. was, since it it no longer there – and to do that we can turn to the maps at Greater Philadelphia Geohistory Network; look at the 1910 map therein and you will see that Dark Run Rd was what is now the portion of Cheltenham Ave running to the south of Wissinoming Park and its nearby graveyards.  (there is also a Hexamer Survey map of Dark Runs Mill, Briggs and Bros., from 1874, that shows quite clearly that there was industry here, but also, as is noted at the outer edges of the map, there was also “meadows” and “farmland” and “woodlands” directly adjacent to those facilities – as is noted on the plan: “Situated on Dark Run Creek, about 1/2 mile above Frankford, 23d Ward, Philadelphia” and “Buildings erected 1869 and 1871…”; Dark Run Creek was also called Tackawanna Creek, and also Little Tacony Creek according to “Old Towns and Districts of Philadelphia“, by William Bucke Campell, published in 1942)

But it wasn’t just trees and wetland plants growing up around there.  There were also flowers being cultivated in the area near Wissinoming Park.  In the middle part of the 20th century, there was a nursery at Frankford and Devereaux.  It’s indicated on a 1929 map (as “F. H. Worsinger. Jr. Green House), and also on 1942 and 1962 maps (those maps are available via the Greater Philadelphia Geohistory Network), and was right across the street from the Frankford Yellowjackets stadium (the Frankford Yellowjackets were a professional football team based out of Frankford) – the stadium at Frankford and Devereax burned down in 1931.

This nursery (Worsinger, that is) most likely supplied materials for the nearby cemeteries, and perhaps that’s why I’ve been unable to turn up much about it, since it would’ve been a highly localized business, and might not have advertised much, nor published catalogs (I’ve looked in the collections at the McLean Library at the Pennsylvania Horticultural Society and haven’t found anything about F. H. Worsinger, nor any kind of nursery with a name like that)

Mr. Worsinger was, however, a reasonably prominent man – as is noted in volume 15 of the Journal of Economic Entomology (published in 1922), he was “locally in charge of the Japanese beetle work, Bureau of Plant Industry, Pennsylvania Department of Agriculture.”

There was another nursery nearby, that could’ve been supplying the cemetery with its bouquets and greenery.  William B. Koehler was a florist on Bridge St., between Darrah and Duffield, with numerous greenhouses (as can be seen in the 1929 map here).  These would likely have supplied the flowery needs of Frankford’s living citizens, and quite likely would have been beautifying the homes of those who were belowground, too.

But there’s more… in addition to the wetland plants and the cultivated trees and the flowers for sale, there were dry, weedily growing open areas there, too, as is indicated by a collection (also at the Academy of Natural Science’s herbarium), from the 13th of October of 1927, by Walter Benner, of the plant Amaranthus spinosus.  Benner made this collection at Frankford Ave and Devereaux St. (that is, where the Yellowjackets stadium stood), and noted the habitat as “Waste ground” (that is, an area like a vacant lot, or perhaps an actual vacant lot – or perhaps just a weedy parking area, but regardless, an open, untended area).  And also at the Academy, there is a collection of wild strawberry (Fragaria virginica), from “burned-over edge of thickets along Wissinoming Creek / Tacony”, that was made by J. W. Adams and Thomas Taylor on the 2nd of May 1926.   And in Keller and Brown’s 1905 Flora of Philadelphia, they note “Aegopodium podagraria … Waste Places.” with a locality of “Dark Run and Frankford”.  And so, while there were plants that were planted and landscapes that were cultivated, there were also areas that just grew up there on their own.

This area had a history of horticulture well prior to the 20th century, I should say.  The Caleb Cope nursery, where Thomas Meehan worked, was a bit farther towards the northeast, at Cottman and Frankford – it was there in the 19th century, predating the cemeteries and parks down the way in Frankford, and Thomas Meehan, the eminent nurseryman of Germantown, worked there early in his career, in the late 1840s.

There was still an agricultural aspect to that area, even into the 20th century, as the following collection label (from, yet again, the Academy of Natural Science’s herbarium) indicates:

Amaranthus spinosus
“weed in open ground about barn
along Cottman St. S.W. of Holmesburg”
Bayard Long
26 Oct 1916

And there also would have been scrubby areas here, in the 1930s, as is indicated by the record of a Brown Thrasher nest (“Wissinoming, 4 highly incubated eggs”), noted by Richard Miller in his paper, “the Breeding Birds of Philadelphia”, in volume 51, number 7 of the Oologist (“for the student of birds, their nests, and eggs”), published in 1933.  And there certainly were wide open areas, as is indicated by the aerial photo here, from 1927:

Wissinoming Park remains to this day a site of botanical interest – there is a pair of southern red oaks (Quercus falcata – these trees were pointed out to me by Tony Gordon, by the way) that are possibly the largest in the city, and there are other enormous oaks, a very large English (or German, depending on whom you ask – but either way it’s Quercus robur) oak in the northeast part of the park, and nearby to that is a very large swamp white oak (Quercus bicolor).  There are also two very good sized ginkgos, and a nice osage orange (Maclura pomifera), too.  And along the “creek” at the Charles St. side of the park, there is a row of catalpas – based on the size of their seed pods (they’re over a centimeter wide), they’re most likely Catalpa speciosa, the northern catalpa – there’s a number of them lined up there, like a screen, awning off the stream and its riparian boundary from the rest of the park [NB: there are some Catalpa bignonioides, the southern catalpa, in the park as well; along the path leading to the “creek” there are two catalpas on either side, the one on the south side is C. speciosa and the one of the north side is C. bignonioides; these are differentiable based on bark characteristics (bignonioides is rough, speciosa is ridged), seed pod width (bignonioides generally less than 1cm across, speciosa generally wider than 1 cm across, and phenology – speciosa flowers before bignonioides; on the 9th of June 2014, the speciosa is already dropping its flowers while the bignonioides buds are barely even expanded; in 2015 I looked pretty closely at the flowers of both these species, and they look pretty much the same].  There are also some pignut trees (Carya glabra) in the park – these are notable if only because they aren’t commonly seen in parks (they are difficult to transplant, and so need to be grown from seed, thereby making it difficult to grow them in a park planting), and even moreso because the squirrels clearly like them so much – when we were there, at Wissinoming Park, on the 25th of June, the ground below them was littered with hickory husks, having been industriously nibbled by these little gray rodents.

For a quick note on another Carya, C. illinoinensis, commonly known as the pecan, from the “Short Sketch of Philadelphia Trees”, from John Harshberger’s 1899 The Botanists of Philadelphia and their Work:

“Nuttall’s Pecan Tree. An old pecan tree, one of the most famous in the city, stood, until recently, on the grounds of the M. E. Church, Germantown and High Streets. The seed was carried by Nuttall, the botanist, from Arkansas.”

(that church is now the First United Methodist Church of Germantown)

And as for those catalpas mentioned above, they are a good size, but not enormous – though these trees do have the potential to grow to great size around here, as an article in the Gardener’s Monthly (volume 20, from 1878) attests, referencing a northern catalpa growing across town, in Fairmount Park:

A Large Catalpa. – Mr. Horace J. Smith writes: “I measured a Catalpa tree in Fairmount Park, on the river drive, west side, this morning, and found it to be thirteen feet in circumference, at an average of one foot from the ground (it is on a hillside), showing a trunk four feet diameter. Would a section or slab be of interest?”

[What will those Western friends think who believe Southern Indiana produces the only hardy Catalpa. Though Mr. Smith does not say so, we can assure them that this Pennsylvania tree is not growing in the mammoth conservatory in Fairmount Park, but is actually in the open air, and has probably been there through a hundred Winters. How many annual rings has it, Mr. Smith? But we hope there will be no attempt to take a slab from it. Better let the old Catalpa stand.]

And as for the osage orange – a Landreth‘s seed catalog from 1832 covers it well:

“A splendid forest tree: the leaves of a beautiful shining green, and the fruit a most singular appearance; discovered by Lewis and Clarke, when on their western tour.

Native soil: Arkansas  $1.00/pc”

(the above was transcribed from a copy at the McLean library)

And Frederick Pursh supplies a bit more information on the Osage Orange, in his Flora Americae Septentrionalis (1814):

“About the village of the Osage Indians a few trees have been planted, from which one has been introduced into one of the gardens at St. Louis on the Mississippi. Perfect seeds from the last-mentioned tree were given by Mr. Lewis to Mr.  M’Mahon, nursery and seedsman at Philadelphia, who raised several fine plants from them, and in whose possession they were when I left America.”

And a brief note on Quercus falcata – this tree is also called the Spanish oak, and a tree by that name was mentioned by William Penn as being here in the 1680sQ. falcata is also listed in William P. C. Barton’s 1818 flora of Philadelphia (“The finest timber tree among the oaks.  In all our woods.”), but there is another tree that Barton calls “Spanish oak” (this is the common name he gives to Q. palustris), and he gives the common name of “red oak” to Q. falcata; Q. rubra, which we would call “red oak” today, he calls “scarlet oak”.  To further complicate and confuse things, in Ida Keller and Stewardson Brown’s 1905 flora of Philadelphia, they list “Spanish oak” as being in Philadelphia (“Byberry … Grays Ferry … 52d Street Woods … Lancaster Pike”), but they give it the latin name of “Q. digitata” (it is also listed under that name, and as being in Philadelphia, in Thomas C., Porter’s 1903 Flora of Pennsylvania); in the copy of Barton’s 1818 flora that is in the botany department of the Academy of Natural Sciences, this name (digitata, that is) is written in the margin next to the section for Q. falcata.  Q. falcata is also in Edgar Wherry’s “A check-list of the flora of Philadelphia County, Pennsylvania” (published in Bartoniathe Journal of the Philadelphia Botanical Club, vol. 38), and this came out in 1969.

Point being – it is complicated tracing back a plant through the literature, but it can be done, and in this instance, we see that Quercus falcata has been here for quite some time, and was reasonably common, even though it is not a tree I commonly see in Philadelphia now.

Wissinoming Park and the area around it has changed drastically over the past couple hundred years – once comprised of open areas with wetlands, of a major estate with streams running through it, of farms and creeks and forests, too, much of this land has proceeded to be covered over and filled in by housing for the living and dead alike.

But among it all, the expansive green that was here when Robert Cornelius planted thousands of trees for his estate in the mid-19th century still breathes open.  Kids play, people sit and talk; barbequing on warm nights, or just walking through when it’s too cold to sit – this vast open oasis covers history, grows from history, and still it is an active part of the community around it, integrating what was here before with what is here now.

Walking among trees that were planted under the direction of the man who took the first photograph of a living human, looking at the section of his estate that was cut off to become a cemetery, gazing over the rink that was once a pond, we can see the changes that have arrived, and even though we don’t need to see or know any of this in order to be a part of the landscape that is there today, seeing the past lends a depth to the present that allows us to see connections that would otherwise lie unseen.

To read about some other parks in Philadelphia, see here:

Hunting Park

West Fairmount Park (Michaux Grove, specifically)

Cresheim Creek

The Wissahickon (its hemlocks, specifically)

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

Library landscaping

If you walk along the 19th Street side of the main branch of the Philadelphia Free Library on the Benjamin Franklin Parkway, you’ll see a row of plants that, though composed of three different species, all have a certain set of similarities.  And if you walk along the 20th Street side of the library, you’ll see the same thing – three different kinds of plants, one somewhat tall, a tree about 15 or 20 feet high or a bit more, and another, a bit smaller, in the 10 to 12 foot range, and then another, a smaller bush, about waist high.

One of them, the tallest, is a hawthorn, a Crataegus, that is most likely the Washington cultivar (given that its leaves are pretty big); an other, the smaller sized one, is Pyracantha, which sometimes goes by the name “firethorn”, but in my experience more often just goes by “Pyracantha”; the third kind of plant there is the toothache tree, or prickly ash.  There are a number of names and three different sizes there, but these plants share some similarities.

All of them, as you will see if you go by there about now, have bright red berries – attractive to birds, serving for dispersal, they also make for a cheery red that draws the eye to this row of plants, especially now as leaves are falling.  They also all have sharp structures jutting out from them – two of them have thorns, one of them has spines, and all of them are armed.

What are spines, and what are thorns, and how do they differ?  To explain this, we need to back up a little bit, to explain how plants work, how they develop, how they grow.

Plants are modular – they grow in sections (modules) along the stem, and each section contains a node and an internode.  The node is where the leaf and branches or buds come out, and the internode, as you might guess, is the part of the stem that is between the nodes.  At the nodes is where we have leaves coming out, and also branches or buds.  If you see a leaf, right next to it there will be an associated branch or bud, or a scar marking where one had been.  And if you see a branch or a bud, right next to it there will be an associated leaf or a scar marking where one had been.  And their arrangement is standard – the branch or bud or their remnant scars will be distal to the leaf (distal means toward the tip of the main stem), and the leaf or its remnant scar will be proximal to the branch or bud (proximal means away from the tip of the main stem).  If you look at a plant, you will see this pattern.

There’s an additional set of structures that are important to our story here – stipules.  Stipules are leaf like structures at the base of a petiole (a petiole is the stem of a leaf), and while we don’t know quite what they do for the plant, they frequently help us (botanists, that is) identify plants, since their presence or absence, or shape or size, can be diagnostic for certain species.

These various organs can be and often are modified, evolutionarily, into different structures – a branch might get sharp at the end, a leaf might gain points, stipules might turn into a defensive arm… and this is what we infer has happened in the ancestors of the plants that now grow along the library.

Hawthorns have thorns, as you might guess from the name – thorns are modified branches, and so if you look at the base of a pointy thing on a hawthorn, and look at the side that faces away from the tip of the branch (the one upon which the thorn is inserted), you’ll see either a leaf or a leaf scar.  Or, for some thorns on a hawthorn, they will be at the very end of the branch – that is, the tip of the branch itself is modified into a thorn.

Pyracantha have thorns, too, which you can see evidence for yourself if you look at their bases, to see the remnant leaf scars, or leaves even, perhaps, if they persist.  Or you will see that the thorns are at the tips of branches, for some of them.

The toothache tree, distinct from the species mentioned above, has spines – stipular spines, actually.

You might think at first, that the toothache tree has prickles.  Prickles are outgrowths of the  epidermis that are, as are thorns and spines, sharp at the end.  You can find prickles on roses, or blackberries, or raspberries – and you can differentiate them morphologically from thorns or spines because they (prickles, that is) are found throughout the internodes, as compared to thorns, which occupy the geography of the branch, from which they are evolved, or spines, which are where a leaf would be – both thorns and spines are at the nodes, prickles are in the internodes.

If you look at a toothache tree that’s aged a bit, it seems that the sharp points arise throughout the internodes, which would make you think that they’re prickles.  However, if you look at younger branches, and look at the bases of the leaves there, and you select a series of them from younger to older, you’ll see that these spines are developed from the stipules, at the bases of the leaves.  They’re stipular spines, as you can prove to yourself by looking.

And so, here by the library, we have this trinity, repeatedly growing in lines up 20th Street and down 19th Street – three different species representing two different families (Pyracantha and hawthorn are in the Rosaceae, toothache tree is in the Rutaceae), all with bright red berries and sharp points (which develop and have evolved distinctly across these family’s evolutionary lineages).

The bright red berries are attractive, but the sharpness protects them – an interesting metaphor for a landscape that encircles a library, I think: the fruit of the tree of knowledge is attractive, but there is a cost, it is sharply protected by the branches where you find it – and whoever gets in there to take it in, to eat the fruit, is then in its service to disperse it, to thereby perpetuate it.

I have no idea if this metaphor was intentional on the part of the landscape designers who originally decided on these plantings decades ago, and it may well be that they just wanted plants with bright red berries in the fall and into the winter, and that they wanted a variety of heights to provide texture to this urban landscape, and that what was available from the nursery all had thorns or spines.

But nevertheless, they provide a keen starting point for dispersing an explanation of the differences among thorns, spines, and prickles.

The saucer magnolia

Two hundred years ago, here in the US, the War of 1812 had just begun, and with it came turmoil and tumult.  However, this was also a time of great ferment and excitement – the Academy of Natural Sciences of Philadelphia, an institution dedicated to the advancement of discovery, had just been founded in March of that year, and fewer than ten years prior to that, this country had expanded to reach from sea to sea, from the Atlantic to the Pacific, what with the Louisiana Purchase and that followed soon thereafter by Meriwether Lewis and William Clark’s expedition out west, to explore those newly acquired lands.  Clark and Lewis, respectively, made maps and sent back ethnographic specimens, and birds, and plants – and the vast majority of those plants are now here in Philadelphia, having arrived, by various means, at the Academy of Natural Sciences.  Two hundred years ago was a time of troubles, but also of growth, expansion, discovery, here in the new world, and that sense of discovery, and some of those specific discoveries, still exist today.

Over in Europe, there was also war two hundred years ago – at this time, 1812, it was the Napoleonic wars, with armies sweeping back and forth across the continent, ravaging as they went.  However, within a few years, Napoleon quite literally met his Waterloo, and so all of his employees, the soldiers that worked for him included, had to find new lines of work.

One of them, one of Napoleon’s soldiers, was a horseman, a chevalier, named Etienne Soulange-Bodin.  Soulange-Bodin had therefore, as you might expect, traveled Europe, and he had seen the sights of the continent on this grand tour, but among the carnage and violence of war.  However, among it all, he loved flowers and plants and trees, throughout, and as he writes (and is quoted/translated in Neil Treseder’s 1978 book, “Magnolias”): “The Germans have encamped in my gardens.  I have encamped in the gardens of the Germans.  I visited the collection of Schönbrun (Vienna), Schauenburg (near Minden), Stuttgart and Petrowski (Moscow).”  And he then a bit later says that “It had doubtless been better for both parties to have stayed at home and planted their cabbages.”

And so, as you might guess, when Soulange-Bodin stopped being a soldier, he went on to become a horticulturalist – and one of the best that France had to offer, ultimately going on to found the Royal Institute of Horticulture at Fromont.  Fromont was magnificent, and Soulange-Bodin was in interesting guy – as we read in J. C. Loudoun’s “Gardener’s Magazine”, vol 9, 1833 (p. 141):

“The Villa of Fromont, on the Seine – M. Soulange Bodin combines, at Fromont, an elegant villa residence with an exotic nursery, and an institution for young horticulturists.  M. Soulange Bodin, like M. Vilmorin, is at once a skilful cultivator, a marchand grenetier (seedsman), a scholar, and an accomplished gentleman.  As connected with the army, he has been all over Europe ; and having been long (to use the Prince de Ligne’s phrase) under the influence of the jardinomanie, wherever he went, the gardens were the main objects of his attention.  At one time he had the principal management of the gardens of the Empress Joséphine at Malmaison.  On M. Bodin’s retirement to Fromont, in 1814, he commenced laying it out in the English manner, and so as to combine the picturesque scenery of the park with the profitable culture of the nursery.  The grounds exceed a hundred acres of a surface gently varied, and sloping to the Seine.”

Soulange-Bodin had an enormous variety of plants, some that came in from distant lands – he had the Yulan magnolia (which we would now call Magnolia denudata), a tree with lovely white flowers, native to eastern China, that had been cultivated in China and Japan for centuries prior to its introduction to Europe in 1780 by Joseph Banks.  He also had the Purple Lily-flowered magnolia, a shrubby magnolia with purple flowers – originally native to China, it had been introduced to Europe by Carl Thunberg in 1790.  (the above information is all from Treseder’s Magnolias (1978), by the way)

He looked at these plants growing in his garden, and knowing that one could take pollen from one tree and place it on the stigmatic surface (the receptive surface of the female part of a flower, that is) of an other, and thereby combine traits from distinct plant lines into novel combinations of characters, he did just that – he wanted to put the purple flowers of Magnolia liliflora (which he called Magnolia discolor) onto the tree habit of Magnolia denudata (which he called Magnolia yulan), and he was successful, as is reported in the 5th tome of the Mémoires de la Société Linnéenne de Paris, published in 1827, where following announcement was made:

“By the combination of Magnolia yulan, providing the seed, with the pollen from Magnolia discolor, the gardens of Fromont have seen the birth, the growth, and the taking of its place among the varied cultivated plants that we admire, a new species remarkable by its arborescent habit, its beautiful foliage, and especially by its large and brilliant flowers where the virginal white is colored with a purple tint.  My honorable Confreres have given this beautiful species the name Magnolia soulangiana.” (translation mine)

Furthermore, in the Bulletin des Sciences Agricoles et Économique, Tome VI, (Paris; 1826), it was mentioned that Etienne Soulange-Bodin had announced his creation to the world, or, at least to the Linnean Society of Paris – this was covered in more detail in the publication, Relation de la cinquième fête champêtre célébré le 24 mai 1826 in: Comte-Rendu des Travaux de la Société Linnéenne de Paris (1826), where Soulange-Bodin states:

“It is with the joy of an innocent triumph that I have the honor, sirs and dear brothers, of saying to you a word about the beautiful hybrid product that I have recently obtained in my cultures.  It is a new Magnolia, provided by the seed, of M. praecia, or yulan, fertilized by the pollen of M. purpurea, or discolor.” (translation mine)

As Neil G. Treseder points out in his book “Magnolias” (1978), “It should be pointed out here that the date 1826 apparently referred to the initial flowering of the particular hybrid seedling which Soulange-Bodin had selected to perpetuate his name.”  Therefore, the actual act of hybridization would have taken place a fair bit earlier, probably around 1820, given that it took about 8 years (more about that below) to get seeds from the plant that came from this initial hybrid.

There was tremendous excitement around this new plant.  Pierre-Joseph Redouté, in his 1827 work Choix des plus belles fleurs, provides an exquisite illustration of Magnolia soulangiana:

Image from the Royal Horticultural Society Lindley Library print collection ( )

Redouté was the plant illustrator of the 19th century – he worked with Empress Josephine at Malmaison (her garden), and Francois Andre Michaux, and his rose illustrations are justifiable legendary and a touchstone for rosarians to this day.  This book, the Choice of the Most Beautiful Flowers, was his selection of the most beautiful flowers that existed.  And this included a new magnolia – Magnolia soulangiana, which he had gotten right from the source (On p. 11 of Redouté’s Choix des plus belles fleurs, it is noted that the flower came from Soulange (“Elle a ete obtenue par M. Soulange-Bodin, a Fromont“)).

Word quickly spread across the channel – in The Atheneum; or Spirit of the English Magazines (p. 487) – vol VII, second series, April to October 1827

“A new species of the Magnolia has been produced by the Chevalier Soulange Bodin, President of the Linnean Society of Paris.

This elegant production to which the Linnean Society of Paris has very properly given the name of Magnolia Soulangiana is only in its second year, and it is not yet known whether the variety will become constant in its form and constitute a new species, – a fact which next year’s produce will decide.”

The plant itself arrived in England quickly, as we see from the Botanical Register, vol. 14, published in London in 1827:

“A very handsome variety of the Yulan Magnolia, obtained, as we are informed by the Chevalier Soulange-Bodin, in his Garden at Fromont, from a seed of M. Yulan, which had been fertilised by the pollen of M. obovata.

Our drawing was made at the Nursery of Messrs. Young, of Epsom by whom the variety had been procured from M. Soulange.  It has been so short a time in this country that little is known of its good qualities except by report…””

The nursery mentioned above was quite excited about this new plant, as is indicated by the following report, from vol. 5 of Loudoun’s “Gardener’s Magazine” (published in London in 1829):

“Messrs. Young have bought the entire stock of Magnolia Soulangiana from M. Soulange Bodin for 500 guineas, in consequence of which that fine tree will soon be spread all over the country.”

This was a new plant, and a beautiful plant – and horticulturalists in centuries past, as they do to this day, respond enthusiastically to novelty, and to beauty, and the horticulturalists of  England responded to the introduction of Soulange’s magnolia by buying them up.

And now, on to America…

By 1832, this magnolia was in the US, as is indicated from its listing in the Periodical catalogue of greenhouse shrubs, vines, herbaceous plants, and bulbous roots: cultivated and for sale at the Linnean Botanic Garden, Flushing, near New York, William Prince & Sons, Proprietors that year (thanks to Maggie Graham of the California Garden & Landscape History Society, for guiding me towards that reference, and to Janet Evans, of the McLean Libray of the Pennsylvania Horticultural Society, for guiding me to Ms. Graham’s guidance).  You’ll note that the price of this plant is $8/piece – as Joel Fry (of Bartram’s Garden) has pointed out, this is extremely expensive; he notes that most trees or shrubs at that time were 50 cents or a dollar per plant, and that a rare and/or new plant might be $5 or so, and therefore the price, eight dollars, is indicative of the rarity and the novelty of the Magnolia soulangeana, when it first arrived in America – excitement surrounded it, as did the dollars.

I note that those plants growing in the Linnean Botanic Garden in 1832 would most probably have been from cuttings from Soulange-Bodin’s original hybrid, or from cuttings derived directly therefrom, as his (Soulange-Bodin’s) original tree did not set seed until 1834, as is noted in Daniel Jay Browne’s 1846 book, “Trees of America” (p. 20):

“At Fromont near Paris, in front of the chateau of M. Soulange-Bodin, stands the largest plant of the Magnolia conspicua in Europe.  It measures over forty feet in height, and twenty four inches in circumference, two feet from the ground ; and the diameter of the space covered by the branches is more than twenty five feet.  It flowers magnificently every year, at the end of March and beginning of April, and the perfume of its blossoms is perceived for some distance around.  It was from the seeds of this tree that sprang the far-famed variety Magnolia conspicua soulangeana, the leaves, wood and general habits of which, are allied to those of the parent tree;  but the flowers resemble in form those of the Magnolia purpurea, or of the Magnolia purpurea gracilis, and the petals are slightly tinged with purple.  This variety was accidentally produced by fecundating the flowers of the Magnolia conspicua with the pollen of those of the Magnolia purpurea.  The original plant of the Magnolia conspicua soulangeana, at Fromont, is more than twenty feet in height, and though it flowered several years before, it did not ripen seeds till 1834.  The seeds have been sown, and some new and interesting varieties produced from them.”

And so we know that by 1832 this tree was in the US, at Prince’s nursery in Queens, NY (i.e, the Linnean Botanic Garden), and that these specific plants were most likely direct descendants, clones, actually, from the original tree grown from the hybrid seed developed at Fromont by Soulange-Bodin.  (note also that the above quote indicates that it took about 8 years for Soulange-Bodin’s original hybrids to set seed)

And by 1836, we know it was in Philadelphia – as is indicated from its listing in Robert Carr’s Periodical Catalogue of Fruit and Ornamental Trees and Shrubs, Green-House Plants, &c. Cultivated and for Sale at the Bartram Botanic Garden, Kingsessing, Near Gray’s Ferry, Three Miles From Philadelphia from that year [p. 12; no price; “Magnolia soulangeana” “Soulange’s [magnolia]”].  (thanks to Joel Fry, of Bartram’s Garden, for directing me to that reference – and to the staff of the Library of the Academy of Natural Sciences, and especially Cathy Buckwalter, for getting me access to it)

In that 1836 catalogue, there wasn’t a price listed for Soulange’s magnolia (the other plants in the catalogue had prices associated with them), and from this we can infer also the rarity and novelty of this plant – it wasn’t even clear to the Carr’s how to price it, it was so new.

But might it have been in Philadelphia earlier than 1836?

At the Wyck Historic House and Garden in Germantown, there is a saucer magnolia – you can see its once magnificent size represented by the girth of its base that now pokes a bit up out of the ground.  I rarely see saucer magnolias with trunks of the width of the Wyck example, and so I can’t judge clearly its age, however, based on general extrapolation from what I’ve seen of younger trees, I wouldn’t feel like I’m putting my neck too far out by saying that this is a 19th century planting and perhaps, even, possibly, one that might date to the earlier half of the 1800s.

The Wyck house dates to the 17th century, but the key part of its history to our story here is its 19th century owners, Jane and Reuben Haines.  Both were ardent lovers of plants, gardens, the natural world – Reuben was Corresponding Secretary of the Academy of Natural Sciences of Philadelphia from 1813 until he died (in 1831), and Jane made a garden at Wyck of stunning beauty and depth.  She was creating this garden in the 1820s and 1830s – that is, when Magnolia soulangeana first came to be, and first came to the US.

And, as I was informed by Nicole Juday (Nicole is a gardener, historian, and all-around extraordinarily knowledgeable person): “From everything I know the Haines’ only got plants from Philadelphia and from Flushing, NY. To my great sorrow I never did come across any receipt for a plant, although there were thousands of invoices for everything else from apples to string to bolts of cloth. But there were a few references to plants “from Prince Nursery” in family papers and lists. Jane Haines’ parents lived in Flushing and she visited there frequently, especially after Reuben’s death.”

And so we find a Magnolia soulangeana at Wyck that is quite large, indicating its great age, and we know that Jane Haines was buying materials in from the “Prince Nursery” (i.e, the Linnean Botanic Garden indicated above), and we know that they, the Prince nursery, had this tree very early on, and that they, the Prince nursery, quite possibly (likely, even, one might say) had the original cross of this plant, the one that was derived from Soulange-Bodin’s garden – and we know that Jane Haines was planting plants at Wyck in the 1830s.

And so, while this is all, at this point, evidence that is suggestive without telling, it does lead one to think that this tree at Wyck may well be one that directly connects to Soulange-Bodin’s garden – not a cousin, not just a sibling even, but possibly an identical twin of the flower illustrated by the illustrious Redouté.  We are still looking for further evidence, hopefully more conclusive, that this is (or is not) the case, but until then we can build a story of this tree created by the hand of former soldier, who turned his swords into plowshares and developed one of the greatest gardens of France, and therefore of Europe, whose tree ultimately found its way across the Atlantic to the yard of a Quaker, a pacifist, here in Philadelphia.  Having followed years of war, but also times of exploration and discovery, this peaceful garden in Germantown, that still exists to this day, holds not just memories, but living history of a time past gone, but still alive.

But it is not quite the original planting that is still alive, I should say – this saucer magnolia had aged, as do all things, even trees, and it had rotted quite a bit on the inside (which is why I can’t count the rings to see for sure how old it is), and so the main trunk had to be taken down recently.  However, there are new stems coming up and out from its remains, stems that are being carefully tended by Elizabeth Belk, the current gardener at Wyck – and she is also putting her efforts towards propagating this tree, by air layering, so that this magnificent plant that may well be immediately descended from the first of the saucer magnolias can live on, and perhaps even live elsewhere, too.

By the 1840s, the Magnolia soulangeana was quite common in the US.  In the 1841 and 1850 editions of Andrew Jackson Downing’s Treatise on the Theory and Practice of Landscape Gardening, there is a “list of hardy and showy shrubs which are at the same time easily procured in the United State.”  Included in this list is the Magnolia soulangeana, whose common name is given as the “Soulange Magnolia”; it is also indicated as being a large shrub, and being purple.  It being noted as a shrub indicates its relative novelty – these plants hadn’t grown into their full tree size yet.

Earlier in the treatise, there is a more detailed discussion of this plant, and its parents, too:

“The foreign sorts introduced into our gardens from China are the Chinese purple (M. purpurea) which produces an abundance of large delicate purple blossoms early in the season, the Yulan or Chinese White Magnolia (M. conspicua) a most abundant bloomer, bearing beautiful white fragrant flowers in April, before the leaves appear ; and Soulange’s Magnolia (M. Soulangiana), a hybrid between the two foregoing, with large flowers delicately tinted with white and purple.  These succeed well in sheltered situations in our pleasure-grounds, and add greatly to their beauty early in the season.  Grafted on the cucumber tree, they form large and vigorous trees of great beauty.” (p. 254)

This tree was becoming quite popular and it became quite common, too, and this has continued on, up until the present.  Today, the saucer magnolia, as this tree is generally now called, is extremely commonly seen as a park or lawn planting, and there are dozens of cultivars available (as is noted by Michael Dirr in his Manual of Woody Landscape Plants (1998)).  If you go to the northwest corner of Rittenhouse Square, in downtown Philadelphia, there are two lovely ones that have been there for a few decades (the one to the east is less than 40 years old, the one to the west a bit older than that – this is indicated from their respective presence/absence in planting maps of the park, one from the 1960s and the other from the 1970s).  And if you go pretty much anywhere in the city, this one or others, you will see the saucer magnolia flowering brightly in the spring – it is a hardy grower with beautiful flowers, and so it is commonly planted.

It is such a strong grower that it has naturalized in Ohio, as a matter of fact – it has been found growing on its own near a cemetery in Cincinnati, Ohio – Spring Grove Cemetery, in October of 1995, to be a bit more exact, in a “weedy woods” – as was documented by Michael Vincent and Allison Cusick in their 1998 paper “New Records of alien Species in the Ohio Vascular Flora (Ohio Journal of Science 98(2), 1998)

And so we have a tree that is now extraordinarily common – there are dozens of cultivars, they are planted all over in parks and yards in cities and suburbs, all over, and it has even naturalized here, in the US.

But this is not always how it was – this is a tree, a hybrid, whose parents traveled separately to Europe from Asia, to come together in a garden not far from Paris, to be united by a man who had soldiered across Europe but retired to live among flowers, a tree that then went on, this beautiful and strong plant, to enter into commerce at the highest price, at some point to be bought by a Quaker, a pacifist, in what was no longer quite the new world but was certainly new to this plant, to grow here in Philadelphia, and to then, to go on, to recently fall apart from the inside, but to then to grow anew, and to continue to survive, with help and care, to live on in a changed world that is everchanging onwards.

For a video on saucer magnolia propagation, see here:

Oakland Cemetery

In between Friends Hospital and Greenwood Cemetery, just a bit off Roosevelt Boulevard in Philadelphia, is Oakland Cemetery.  Friends Hospital, founded in 1813, is the oldest private psychiatric hospital in the US, and it also has a beautiful landscape – with its azaleas along the way down to Tacony Creek behind it, with its enormous American elm tucked away into a corner behind one of its buildings, and with the many other trees and flowers dotting and shading it throughout, it’s a surprising little refuge of calm and color in the city, as traffic along the Boulevard rushes by, just beyond the gates and fence of the hospital’s grounds.  If you go back behind the buildings and down that road that is lined with those azaleas that bloom in the spring, and you take a left turn at Tacony Creek, you’ll eventually get to Fishers Lane.  And if you then take a left there, you’ll get to Ramona Ave, and then, a bit more along, as you walk along Ramona, you’ll see Greenwood Cemetery on your right.

Greenwood Cemetery was, in centuries ago, the property of Benjamin Rush, physician, signer of the Declaration of Independence, and advocate of sugar maples and the maple syrup that can be derived therefrom.  Why was Dr. Rush an advocate of maple syrup?  This was in large part because he was an ardent abolitionist, and didn’t want Americans to be reliant upon sugar from West Indies’ sugar cane, which was reliant, in turn, on slave labor for its production.  There are, currently, some extraordinarily large sugar maples there, at Greenwood Cemetery, that stand as markers to Rush’s advocacy for their products, and for his advocacy for that most basic of human rights, the right to live freely.

In the post-Rush era, this site became a cemetery, Greenwood Cemetery, chartered in 1869, and as the years wore on, maintenance became difficult to keep up, and this place became quite overgrown, and up until recently was somewhat forested, but it has recently been restored and renovated, and is an idyllic spot to walk now.  And in addition to the sugar maples that I just mentioned, there is also an enormous American sycamore there, that based on its size looks to have been planted in the mid-19th century.  American sycamores don’t do very well in sooty air of cities, and so this tree suggests, to me at least, a 19th century habitat that was open and well stocked with clear air.

And in between these two landmarks, in between Friends Hospital and Greenwood Cemetery, is another open area – open amid the swaths of buildings and roads that pack in, through, and around Philadelphia, it is open and green with trees and shrubs and grass, an open space in the city – Oakland Cemetery.

According to the book Philadelphia: A Guide to the Nation’s Birthplace (by the Federal Writers’ Project, in 1937) Oakland Cemetery opened in 1881 (they also mention that it’s 43 acres), however, as I’ve been told by Jackie Childs, the official start date for the cemetery is 1891.   And Jackie is one to know such things – she is the fourth generation in her family to take care of Oakland Cemetery, and is wonderfully knowledgeable as to what is there, and also as to what was there before.

The cemetery was briefly known as Mt. Auburn (as is indicated on the 1895 map here:, but shortly thereafter came to its current name of Oakland (as is indicated on the 1910 map here:, and that is what we know it as now.

In 1895, electric lights were put in, as was recorded in the Journal of the Select Council of the City of Philadelphia, vol. 2 (from October 4, 1894 to March 28, 1895)


Locating electric lights for the year 1895.

Section 1. The Select and Common Councils of the City of Philadelphia do ordain, That the Director of the Department of Public Safety be, and is hereby, authorized and directed to erect electric lights on the following streets and avenues, viz. …”

Following that ellipsis, among the hundreds upon hundreds of streets noted as soon to be having electric lights, we find “south side Asylum pike opposite Oakland Cemetery” listed among them.

If you go there now, you won’t see those lights, but you will see trees that were in the cemetery at that time – at the entrance to Oakland at Adams and Ramona, for example, there is an enormous black oak (Quercus velutina) that, based on its size, I estimate to predate the cemetery.  Also, it has wide and broad spreading lower limbs – this indicates that it has been open grown since its youth, thereby providing evidence that this property was not forested, even prior to its conversion to a cemetery (it would have been a farm – and so we can put together a little story that this now majestic black oak would have, in the mid-19th century, been a scrawny little sapling that was kept alive with, quite likely, the intention of shading cows in a pasture, or farmers on break from working the fields, or the owners as they watched the workers working, perhaps).

Why do those wide and spreading limbs of the black oak indicate this history?  Well, when trees grow in the forest, with other trees nearby, those other trees shade out the lower limbs – and then those lower limbs become weak, and then they fall off, and so we get trees in the forest that are generally tall and straight, growing upwards, with relatively few lower limbs spreading out horizontally (and perhaps with a bit of the oblique).  However, absent those neighboring trees, being “open grown” that is, and absent someone coming along and cutting off a tree’s lower limbs, a tree will branch out broadly, low and spreading, and as the years go by those lower branches will get thicker and larger, expanding in girth as they expand in length, presenting an architecture that looks like it was made to be climbed on or climbed up.  The black oak at the entrance to Oakland Cemetery has just that aspect, and so we can say quite confidently that it didn’t grow up in the forest, but in a field.

If you go a bit farther in to the cemetery, up to the main house there, on your left is an old umbrella magnolia (Magnolia tripetala) – its main trunk has died back, but the suckers that have come up off the roots flower quite well, as the fruits that were there in September 2012 attest.  The umbrella magnolia isn’t native to southeastern Pennsylvania, though it is native to west of here, as Ann Rhoads very persuasively argued in Bartonia, the Journal of the Philadelphia Botanical Club, however it has grown here for quite some time and been naturalized for about a hundred years or so, and it is a reasonably common tree to see planted, or coming up in the woods (I see it pretty often up in the Wissahickon).  This one at Oakland, looking at the base that has died back and from which these suckers has arisen, is one of the largest that I’m aware of around here, and I wonder if it represents one of the earlier plantings of this tree around here.  I should say also that this tree has been growing in Philadelphia for over two hundred years – Magnolia tripetala is listed in the Landreth’s nursery catalog of 1811 [which can be found in the McLean Library of the Pennsylvania Horticultural Society], with a common name of “umbrella tree”, and it’s listed in John Bartram’s “Catalogue of American Trees, Shrubs and Herbacious Plants, most of which are now growing, and produce ripe Seed in John Bartram’s Garden, near Philadelphia. The Seed and Growing Plants of Which are disposed of on the most reasonable Terms.” ([Phila.]: [1783]), as is noted in Joel Fry’s article “An international catalogue of North American trees and shrubs; the Bartram broadside, 1783”, in the Journal of Garden History (vol. 16, no. 1, 1996).

A bit farther down and along, just past the house, you start to see large white ash (Fraxinus americana) trees, growing wide and spreading.  These trees, based on their size, I would estimate to have been planted around the time of the opening of the cemetery in the late 19th century – their placement along its paths also attests to their planting having postdated its establishment.  They also look to have been pollarded.  Pollarding is a process whereby the top of a tree is cut off, thereby allowing side shoots to grow up and out from where that top had been removed – this establishes a broadly arching habit, much like what one might see in an American elm, with branches stretching up and over, and if pollarded trees have been planted along side either side of a road or path, those upward sweeping limbs can meet in the middle, forming a vaulting architecture under which we may walk and cars may drive.  Of course, trees can also lose their tops without the intentional intervention of people, without pollarding that is, and so you have to check that this is part of the landscaping intentions, and isn’t due to wind, or someone accidentally swiping a top or two of a tree as they pass by with a truck or something.  These ash trees at Oakland are pretty much all spraying upwards from points at roughly the same height – this suggests to me that they were managed to look like this (if the breaks were accidental or due to nonhuman interventions, then I’d expect them to be expanding outwards from different heights), suggesting that they were clipped so that they could go on to form graceful ceilings under which mourners could make their ways to gravesites, and also so that Sunday visitors who simply wanted to visit a beautiful park could stroll underneath a sky of green.

Onwards and somewhat southwards, as you go along the path that goes towards Ramona Ave and Fisher Lane, and as you get nearly towards the split point of Ramona and Fisher, you’ll look down on your left and you’ll see a sewer.  I was pretty excited when I saw that for the first time – why was that?  Why was I excited to see this hole in the ground, a hole that pretty much just leads to other holes?  Why on earth (or in earth) would I get excited to see a sewer?

Well, if you look at old maps of this site you’ll find that there were streams that used to run through it – in the 1862 map here:, you’ll see a couple of streams running out of the back of what is now Oakland Cemetery, and one of them, the one to the south, was roughly where Fisher’s Lane splits off from Ramona Ave (and also running along Ramona a bit prior to Ramona’s split with Fisher); the other was up towards the Friends Asylum. The former stream (the one running near what is now Ramona and Fisher) is not on the 1855 map (here:; the latter is.  If we look on the 1843 map here:, both streams are on map, and on the 1808 Hills map (same place as the others), the southern (the one near Ramona and Fisher) stream is there.

There is, I should say, another sewer uphill from that old one – it is newer, and while it does, I’m quite confident, pour its water and other effluvia ultimately into that old streambed marked in those old maps, because it is newer it is not as likely to mark quite as exactly where the stream ran, like that old one does, but was more likely constructed as simple drainage for the road that it accompanies.

And so, that old sewer, and a pretty humble one at that, unlabelled and unadorned, marks the site of a stream that is no longer there – it gives us a physical landmark with which we can pinpoint where that historic stream was, a stream that was limned on old maps and has since been covered up but still carries water, though now underground.  A stream that ran when Benjamin Rush lived here, advocating for abolition, a stream that ran when Friends Hospital opened, a hospital devoted to humane treatment of those who had been treated quite differently prior to that, a stream that ran when this site, Oakland Cemetery, was farmland, with a little black oak seedling far a ways up the hill, now shading the entrance to this city of the dead, but then kept alive most likely with the intention of shading pasture for farm animals, or farm workers, or farm owners – this stream still runs, but the only evidence we see that remains is that humble opening, telling us, quietly, subtly, discreetly, where the history lies beneath.

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

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


Cedar Grove

Hunting Park

Monument Cemetery

Some Plants and Insects of the Woodlands

A different zelkova (Woodlands Cemetery)

Feral landscaping (Woodlands and Mt. Moriah cemeteries)

Basal scars on street trees

If you walk along Pine Street in downtown Philadelphia, from 7th Street to 6th Street, you’ll see a number of trees planted there: various species, of various sizes and ages – with different kinds of leaves and bark, and different kinds of fruits and flowers and seeds – there’s a nice little bit of diversity along that city block, in a number of different kinds of ways, many of which are characteristics of diversity that are commonly noted when people look at trees in cities.  But there is also another kind of variability in the trees on that block of Pine Street, a kind that we don’t often think of when we look at urban trees, and that variability is in the basal scars.

What are basal scars?  Well, as Tom Wessels sagely defines them in his book Forest Forensics, they are “scars at the base of tree trunks created by the removal of bark from fire or some form of impact”.   Basically, they are areas of a tree, towards the base, where the bark was once stripped away and you can see directly to the wood that had been underneath that bark, and the bark has grown up scar tissue around the sides of the wound.

Why does Tom Wessels define them in his book?  Well, in Forest Forensics, as well as an earlier book of his, Reading the Forested Landscape, he discusses how basal scars can be created, and therefore how they (basal scars, that is) can be used to interpret prior land use history.  For example, if there are trees growing on a slope, and there are basal scars on the uphill sides of the bases of those trees, this implies that there was a forest fire there at some point.   Why is this?  As Mr. Wessels explains, the uphill side of a tree trunk is an excellent tool for catching sticks and twigs and leaves as they tumble down a hill – to a botanist, these are plant parts, but to a forester, however, especially one interested in fire ecology, this is debris that is fuel for fires.  And as this debris, this fuel, is piled up against the trunk, and moreso on the uphill side, then that uphill side will generally burn hotter than the other sides of the trunk – and possibly hot enough to burn away the bark, and then to leave a scar.  Therefore, scars on the uphill sides of trees on a slope implies a forest fire at some point in their history.

A certain basal scar orientation can also imply logging – if there are basal scars that are facing each other, that is, if trees that face each other have basal scars directly across from each other, this implies a logging history.  Why is this?  Again, as Mr. Wessels explains, when loggers were dragging out logs from trees they had cut down, they would have taken them along logging roads, and since trees are frequently found in forests, one might expect that there would be trees on either side of those logging roads.  And, since those cut logs would quite likely have bumped up against those trees on either side of a road, well, one would then expect logging to cause there to be basal scars on trees on either sides of logging roads, and therefore opposing basal scars are considered one line of evidence to support a history of logging in a forest stand.

OK, so on Pine Street between 6th and 7th Street, in downtown Philadelphia, there has not been logging any time recently, and so these basal scars are most likely not from some Philadelphian Paul Bunyan’s lugging of logs through the city streets.  And, while there may well be house fires on that block with a reasonable frequency, those fires are unlikely to spill onto the street, and therefore unlikely to scar the trees there.

So what is it?  What left those scars?  Vandals?  Construction workers as they build or mend houses and accidentally bump into the trees with their equipment?  Cars as they drive down the street and occasionally veer onto the sidewalk?  Car doors as they let people out?    Errant bicyclists careening into arboreal blockades?  Which of these is it?

Let’s look at the evidence…

As one walks east from 7th Street, towards 6th, one sees first a willow oak, and then another one – that first one has a pretty large scar on it, on the west side of the tree; the second does not have any major scarring.  The next tree is an elm, somewhat small (less then 3″ dbh [=diameter at breast height]), with no scars, and then the next tree is a sweetgum, with a scar on the west side of the tree.  This is followed (going eastward), by two Norway maples, both with no scars, and then these two are followed by a Norway maple with a scar on the street side of the trunk of the tree.  This is followed by a ginkgo with a street side scar, and then finally, right up towards 6th Street, there is a sweet gum with a mild scar (not so strong that one can see through to the wood, but a noticeable change in the texture of the bark), and that light scar faces roughly westward, and is somewhat angled towards the street.
If we then walk back towards 7th, from 6th Street, the first two trees we see are sweet gums without any scarring, followed by a London plane with a pretty big scar facing towards the street, and another scar facing east.  This eastward facing scar is at the end of a stumpy branch; it is not on the main trunk of the tree.  After that somewhat mangled London plane, as we go westward now, there is a sweet gum without a scar, followed by a somewhat small London plane (less than 10″ dbh), also without scarring.  The last two trees on the block, before we get to 7th Street, are both willow oaks, and neither have scars.

There is only one tree with scarring on the east side, and that one is the London Plane whose scar looks to have been derived from a branch having broken off (this is because the stump of that branch is still there, providing evidence of its own existence).  All the other scars are either on the west sides of the tree trunks, or facing in to the street.

Of 16 trees on this block, none of them have damage directly on their trunks on their east sides, nor on the sides facing in to their respective sidewalks.  Two of them have basal scars on their west sides, three of them have damage on the street side, and one of them has evidence of light damage at an angle between the street side and the west side.

Traffic goes east on Pine Street, and north on 7th Street – therefore, it makes sense to me to come to the conclusion that the westward facing scars are from cars running into the trees.  The one eastward facing scar, the one that would have come from a broken branch, doesn’t disagree with this pattern, I think, and I’ll get back to that in a minute (depending on how fast you read, that is).  The tree on the southeast corner of 7th and Pine would be especially vulnerable, as someone making a turn there could easily hop the sidewalk and run right into that willow oak there.

The street facing scars are most likely from car doors – and not just any car doors, but more often from passenger side car doors than drivers’ sides.  Note that there are two street side scars (possibly three, if we count the faint one on the sweetgum) on the south side of the street, which is the right side (= passenger side) of the street in the direction one would be driving on this block, while there is only one street side scar on north side of the street, and that one on the north side is accompanied by evidence of a broken branch, and a relatively large branch it is (it’s over an inch across), which implies that the strike that did this had some force to it – perhaps more than an opening door would have caused, and perhaps more likely from it having been sideswiped by a car.  This broken-branch line of evidence also suggests that, as I mentioned above, the eastward facing scar on this London plane doesn’t disagree with the idea that basal scars here are due to collisions with cars coming from the west – breaking off that branch could easily have happened from a collision from a car coming from the branch’s opposite side and snagging that low lying branch right off (it’s only a foot or so off the ground).

But back to the car doors for a moment – one would expect there to be more damage from passenger side doors than driver side doors simply because the driver can see out his-or-her side more easily than that of the passenger’s, and so would be more likely to avoid hitting a tree with their own door, while a passenger would be more likely to pop out the door and, inadvertently, hit a tree with it as it swings out.  And so our evidence fits what makes sense, which doesn’t always happen, and so I like to point out when it does.

To summarize a bit here –  the evidence strongly suggests that these basal scars are from cars colliding with the trees, and also from passenger side doors hitting them (hitting the trees, that is).  If these scars were from vandals or sturdy bicyclists, I’d expect there to be scars on all sides of the trees.  There are not.  And if these scars were from construction or maintenance of the houses on this street leading to tree damage, I’d expect there to be scars on the sidewalk side of the trees.  There are not.  And so, it appears as though the main source of damage to these trees is cars.

This is only one city block of course, and it will be interesting to see if this pattern holds elsewhere.  It also would be interesting to see if we can find evidence of traffic direction changes, etched in the scars of street trees – for example, if a street’s traffic direction changed, but its trees did not, we would expect to see some scarring on the older trees on the opposite side of current oncoming traffic.  Or if there’s places where we might see evidence of a street getting changed from a two-way to a one-way street – older trees would mark the past all the way up to today, the current trees would only record the present and the more recent past.  Or, looking forward, as more bike lanes are put in place, for example as we now have in the south lane of Pine Street (including between 6th Street and 7th Street, the area we’re talking about here), maybe there will be fewer passenger side door bumpings with trees, and we’ll see a reduction in street side basal scars where bike lanes are put in.  Or perhaps we won’t.  One never knows, but eventually we will, if we keep on looking.

Which hawthorns are at Bartram’s Garden, and where are they?

Joel Fry, Curator at Bartram’s Garden, answers these questions, and more….

[please note that hawthorn (= the genus Crataegus) taxonomy contains many uncertainties, and that Joel has noted where modern names are not clearly applicable to historic names and where identification of plants is not clear cut – and hence the use of words like “possibly” and “likely”, inter alia]

The 3 trees southwest of the Bartram House all seem to be Crataegus flabellata, fanleaf hawthorn.

The tree that is southeast of the Bartram House and down the steps from the upper terrace (i.e., in what we call the “Lower Garden”) is likely Crataegus succulenta var. macracantha, fleshy hawthorn.

The tree at the southeast gate to the historic garden is Crataegus mollis, downy hawthorn.

Additionally there are a number of hawthorns planted on the entry drive, and there are others that may have been planted or may be volunteer seedlings.

Along the Bartram village side of the entry lane are many Crataegus phaenopyrum, Washington hawthorn. These were planted in the 1950s by the John Bartram Association. There are also a few isolated Washington hawthorns on the CSX railroad [this refers to the railroad tracks that pass through Bartram’s below grade] side of the entry, that look larger and may have been planted earlier, in the 1940s or 1930s.  But at that date the current entry road to the garden did not exist, so it seems an unlikely place for planting. They might be volunteer trees that sprouted in the brush along the railroad in the first half of the 20th century.  Or they could have also been planted in the 1950s, but grew larger due to better conditions.

There is also a large, old Crataegus crus-galli, cockspur hawthorn along the CSX side of the entry, that recently lost most of its top growth, but still seems alive. This is a very large hawthorn that could easily date to the first third of the 20th c. There are other cockspur hawthorns as volunteer trees throughout the entire site. There is one very near the gate into the administration building and garden barn, and several down along the river bank in the wetland at the foot of the historic garden.

There is another very large volunteer hawthorn along the main CSX railroad line just before 54th and Lindbergh. It grows right on the edge of the cleared bank at the railroad bridge, and is lately partially engulphed in paper mulberries. This hawthorn also looks like a volunteer tree, as it is halfway down the slope of the railroad cut. I saw recently the tree is now covered with a very large quantity of large scarlet fruit. It is different from any of the other Crataegus in the garden, and may be Crataegus pedicellata (C. coccinea), scarlet hawthorn, which has large clusters of large, soft fruit.  This scarlet hawthorn seems to grow like the downy hawthorn with a larger trunk and large, wooly leaves, but much more fruit which is scarlet, rather than yellowish orange. It also looks to be free of the rust or fungus that attacks some of the other hawthorns and their fruit.

Crataegus pedicellata, scarlet hawthorn is one of the hawthorns recorded for the John Bartram period so it would be useful to have more examples, and it may be one of the most attractive/useful of all the native hawthorns.

There are also 2 or more hawthorns in the historic Orchard tract, mostly along the edge of the 1838 railroad cut. These don’t fruit well, and are currently much overgrown,  covered with porcelain berry or other vines, so it’s difficult to identify what they might be.

Additionally, Joel supplies the names of Crataegus that John Bartram used in his seed box lists in the 18th century:

Firstly: John Bartram generally used the genus “Crataegus” to mean what is now called Amelanchier, or Aronia/Photinia, although he also used the genus “Mespilus” to mean some modern Amelanchier.  I think this relates to the great variability of stamens that forced theses several genera into different Linnaean Classes–one of the great failings and confusions of the original Sexual System.

When John Bartram named what are now considered Crataegus he almost always called them some type of “thorn” in English. [These names range from 1754-1769]

Bartram’s “narrow leaved thorn” or “cockspur thorn” = modern Crataegus crus-galli

“broad leaved thorn” = Crataegus flabellata (possibly)

“dwarf haw” = Crataegus uniflora (possibly)

William Bartram’s plant lists add a few more Crataegus species, that were likely growing at Bartram’s Garden. In 1783 he (Willam Bartram, that is) adopted the genus “Mespilus” in describing all the hawthorns. Like his father he used “Crategus” [Willam Bartram’s spelling] for modern  Aronia/Photinia  and some Amelanchier.  [All from the 1783 broadside Catalogue of Bartram’s Garden.]

“Mespilus Spinoza, Cockspur Hawthorn” = Crataegus crus-galli

“Mespilus Apiifolia, Carolina Hawthorn” = Crataegus marshallii

“Mespilus Azarol, Great Hawthorn” = Crataegus mollis (possibly)

“Mespilus Humilis, Dwarf Hawthorn” = Crataegus uniflora (possibly)

[Note: there was a Crataegus named for John Bartram, that was collected, by Alexander MacElwee, at a locality noted as “Lane near Bartram’s old garden” on “June 3, 1901”, and given the name “Crataegus bartramiana, specimens of it are currently at the herbarium of the Academy of Natural Sciences (PH); it was also collected by MacElwee on 20 September 1902 and B. H. Smith on the 24th of May 1905 and the 25th of May 1912 (noted as from “type tree!”).  There is also a record of Crataegus tatnalliana growing at Bartram’s, from a collection at PH, collected by B.H. Smith on the 28th of August 1904, and also a note in Keller and Brown’s 1905 Flora of Philadelphia]

For more about Bartram’s:


Some botanical history