An Ordinary But Very Special Quercus macrocarpa in Paris

Postcard from 1973 showing the Quercus macrocarpa at Jardins de Plantes

In the Trompenburg Arboretum archive, where we keep our letters, I recently found a letter from Heino Heine dating back to 1973. Attached to it was a postcard and herbarium specimens of Quercus macrocarpa. Dr. Heino Heine (1923 – 1996) was in those days Maître de Recherches at the Muséum national d’histoire naturelle in Paris. In his letter he refers to an old specimen in the Jardin des Plantes of Q. macrocarpa, the bur oak. The attached postcard shows a photo of the entrance to the Jardin des Plantes with a stately, tall iron gate and directly behind the gate the crown of the bur oak.

Dr. Heine wrote on the back of the postcard: “Quercus macrocarpa Michx., Jardin des Plantes, Paris. Very tall specimen (just behind the gate at the corner Rue Cuvier/ Rue Geoffroy-St-Hilaire), raised from an acorn brought back from the U.S.A. by André Michaux and planted on this spot in 1811.”

It is not often that one finds a specimen of Q. macrocarpa of that age and size. And certainly not grown from an acorn that was collected in North America by André Michaux.

The herbarium leaves that accompany the letter clearly show the distinctive characteristics of a Q. macrocarpa: broadest above the middle, shallowly to deeply lobed with a pair of deep lobes just below the middle, leaf blade tapering to a narrow base and rounded at the tip. There is much

Distribution of Quercus macrocarpa

variation, however, throughout its native range in the Midwest, from the Canadian border in the north all the way south to the Gulf of Mexico in Texas. Macrocarpa (=big fruits) refers to the huge acorns and this name

Quercus macrocarpa acorns, Reverchon Park, Dallas, TX

was chosen by André Michaux himself when he described the species. How very nice and very special to find this connection between the living specimen in Paris that grew from an acorn in North America and the man who named the species and collected that acorn!

What do we know about him?

In short: André Michaux (1746-1802) was a French botanist who made many botanical explorations in Europe and what was in those days Persia, where he was sent out to collect plants by the French Queen Marie Antoinette.

Herbarium samples of Quercus macrocarpa sent to Trompenburg Gardens by Dr. Heino Heine in 1973

Michaux is best known for his explorations in North America, which resulted in plant introductions to Europe and in two sublime publications.

From 1785 to 1796 he travelled and collected by orders of the French King Louis XVI.

At the time of his travels there was still much turmoil in North America as a result of the recently ended War of Independence (1775-1783), the war between Great Britain and the colonies that later would become the United States of America.

At the same time there was much also going on in Western Europe. The French Revolution resulted in the death of Louis XVI under the guillotine on January 21, 1793.

During his time in America, in between all kinds of political mayhem, Michaux found time to make many collecting trips. Not only plants but also animals were of interest to him. By 1786 he was accompanied by his son François, who in 1790 (the year of the storming of the Bastille) travelled back to France with 14 crates loaded with plants and seeds. André Michaux himself returned to France in 1796, also carrying a great amount of luggage. Sadly enough much of that shipment was lost due to a shipwreck on the way home. So the question arises: were the acorns of the Quercus macrocarpa in

Illustration by Redouté from Michaux's Histoire des Chênes de l'Amérique

the Jardin des Plantes on the shipment of 1790 or that of 1796. Probably we will never know. From the writing on the back of the postcard we know that a seedling from either one of the two shipments was planted in 1811.

In 1801 André Michaux published the great volume: Histoire des Chênes de l'Amérique, ou descriptions et figures de toutes les espèces et variétés de Chênes de l'Amérique Septentrionale, considérées sous les rapports de la Botanique, de leur culture et de leur usage. [1] In this beautifully decorated book Michaux publishes new descriptions of four oak species: Q. macrocarpa, Q. imbricaria, Q. laurifolia; and Q. falcata. A year after the publication Michaux died while travelling to Madagascar.

To honour this great French botanist, in 1818 the English-born botanist Thomas Nutall,[2] who lived and worked in the US from 1808 to 1841, named the swamp chestnut oak Quercus michauxii Nutt.

A quick search on Google Street View shows that the tree is still there. The heavily branched, open tree canopy reaches further out above the street than in 1973. Whenever I get the opportunity to visit Paris again I certainly will pay a visit to the Jardin des Plantes and give a big hug to this ordinary but oh-so-special tree. Usually I am not much of a tree-hugger, but in this case, where do you get the opportunity to be so close to the man that collected the acorn, raised the tree and had it planted?

Google Street View image of Rue Cuvier, showing the Quercus macrocarpa in the Jardin des Plantes

Herbarium sheet of the Quercus macrocarpa specimens collected by André Michaux (photo © Olivier Colin)

Lower right label:
Quercus ramulis suberosis, fol. magnis lyratis, calyce echinata, glande maximo, in regione Illinois
[Quercus with corky branches, big lyre-shaped leaves, cup spiny, acorn big, in region of Illinois]

Vertical left label:
Overcup white oak, Illinois, Cumberland et Kentucky, chêne frisé [curly haired oak]

Lower middle label:
No. 18, Quercus macrocarpon

The type specimen of Quercus oliviformis F. Michx. 1811 (lower left label and lower right label). In 1935 Aimée Camus considered this to be a subspecies of Quercus macrocarpa and attached a label on the herbarium sheet: Q. macrocarpa subsp. olivæformis [3](F. Michx.) A. Camus. Before her Asa Gray already in 1856 considered oliviformis to be a variety of Q. macrocarpa: Q. macrocarpa var. oliviformis (F. Michx.) A. Gray 1856. The fact that Camus changed the status from var. to subsp. most likely has to do with the fact that she had gained knowledge that this deeply lobed leaf type of Q. macrocarpa occurs over the whole range of Q. macrocarpa in the wild (so has a geographical distribution, contrary to botanical varieties that only have a very limited occurrence ). At this moment the opinion is that this leaf type is part of the natural variation of leaf types within the species of Q. macrocarpa. To identify deeply lobed types in cultivation, following the relatively new Group concept, the Oliviformis Group was established. (Image credit: Muséum national d'histoire naturelle)
Quercus macrocarpa in Jardin des Plantes, 2017. Photo © Olivier Colin

With thanks to Olivier Colin in Paris for his input and photos

 

[1] The book can still be obtained: a few antique book shops sell it online for €12.000,00!

[2] Nuttall also had a species of oak named after him: Quercus nuttallii, by Palmer. Now the correct name should be Quercus texana that was named by Buckley. And Palmer and Buckley also had their names turned into oak species: Q. palmeri and Q. buckleyi. The conclusion could be that if one does sufficient good work on oaks, one becomes an oak.

[3] The spelling olivæformis was subsequently changed to oliviformis.