How It All Began



“As well as a flourishing library, the school by 1909 had a wood collection containing specimens of nearly all of Pennsylvania’s native trees and large shrubs. For each species, cross sections and radial and tangential sections had been prepared to show the gross appearance of the wood. The next step was the preservation of samples in alcohol and glycerin so that sections suitable for microscopic examination could be cut. These latter sections were to be especially useful in the study of timber physics (wood technology)." E.H. Thomas, “A History of the Pennsylvania State Forestry School, 1903 – 1929.” p. 67

Wednesday, April 12, 2017

Re-assignment of Family Causes Heartbreak


Hamamelidaceae Liquidambar styraciflua.


Source: Sanchezn - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3057384

This was my favorite scientific name in dendrology class back in college. We had to memorize about 150 tree names, and a few of them still rattle around in my brain occasionally. But Hamamelidaceae Liquidambar styraciflua pops instantly into my mind every time I pass a sweetgum tree. And they're almost everywhere east of the Mississippi, which means that wonderful name rings in my head all the time.

A Sweetgum in autumn. Source: Ontologicalpuppy - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=36757412
I just came across three specimens of L. styraciflua in my documentation project. Instantly the old satisfaction of allowing those sixteen syllables rolling off the tongue in my brain brought back the pleasant memories of collecting leaf samples in the cool autumn air of Nacogdoches, Texas.

But as I checked into The Plant List to confirm the Accepted Name (yes, it is still Liquidambar styraciflua L.) I received a shock. The Plant List had the Family listed as Altingiaceae! What the heck is Altingiaceae? I quickly clicked over to the Catalogue of Life and confirmed that, indeed, genus Liquidambar has been torn from the bosom of the witch-hazel family Hamamelidaceae, and transplanted into the unknown-to-me family of Altingiaceae.

Altingiaceae Liquidambar styraciflua?! Just doesn't have the same ring, the same rhythm. What were they thinking?

Well, according to Wikipedia...
"The name "Altingiaceae" has a long and complex taxonomic history. Some attribute the name to John Lindley, who published it in 1846. Others say that the authority for the name is Paul F. Horaninov, who described the group in 1841. In the nineteenth and twentieth centuries, the family Altingiaceae was not generally accepted. Most authors placed these genera in Hamamelidaceae and this treatment has been followed in some recent works as well. In the twenty-first century, however, molecular phylogenetic studies have shown that including Altingiaceae in Hamamelidaceae makes Hamamelidaceae paraphyletic. The Angiosperm Phylogeny Group recognizes four families in the lineage including Altingiaceae. Cercidiphyllaceae and Daphniphyllaceae are sister. This clade is sister to Hamamelidaceae and these three families are sister to Altingiaceae. The clade is sister to Paeoniaceae."
-  https://en.wikipedia.org/wiki/Altingiaceae
So, the result of the best thinking on this subject is that the inclusion of Liquidambar in the Hamamelidaceae family is invalid, and the fifteen Liquidambar species have been sent to plant purgatory in the single-species family Altingiaceae.

So much the worse for modern-day dendrology students, who will never experience the pleasure of committing Hamamelidaceae Liquidambar styraciflua to memory.

A nice non-typical (spalted) specimen of L. styraciflua. Source: Penn State Xylarium.


Monday, April 10, 2017

An Update on Validation of Accepted Names

I've finished going through and finding all the Accepted Names of the species I've entered into the database. The results are in the tally description on the right.

An interesting note was that on my first pass using ThePlantList.org, I had 110 "unresolved" species names. The Plant List Version 1.1 is current as of September 2013. I then thought to check these 110 against a few other sites that I had not been using, and found that the site "CatalogueofLife.org" was current as of March, 2017. Searching these unresolved names on Catalogue of Life changed about 80 of them to "Accepted" names, about half of which were the same as the unresolved names, and the other half were different.

We live in a wonderful time when we can reconcile our areas of research across several online resources, and get a good sense of just how valid our determinations are.

Another note of interest to those of you who may be interested. I've posted a link called "Database" there in the right-hand column that will give you access to the most current version of the Penn State Xylarium worksheet. So you can see what I've entered into the database and keep up with my progress. Hopefully, I'll finish the data entry sometime this year...only about 8,000 to go.