Bustin’ Up the Scrophulariaceae
By Carol Ann McCormick, Curatrix
One certainty in life is change. Sometimes change is for the better, sometimes change is for the worse, and sometimes change is a neutral pivot. Such is the case with botanical names – though I can attest that rarely do I greet name changes with neutrality. I have a sense of dread when a plant I learned as Diplazium pycnocarpon becomes Homalo something… now what is the new name? Sounds like a dinosaur. Oh right. Homalosorus … wait – it’s changed AGAIN? Well, Diplaziopsis pycnocarpa… is a bit easier to remember for glade fern, but will I truly remember? Unlikely. Panax trifolium – dwarf ginseng – changed to Nanopanax trifolius – I actually like that name change for a tiny plant!
While genus names change frequently (“too frequently” I hear the Greek chorus behind me intone), it is less common for plants to change families. Of course I need to remember that it’s the humans making all these changes – I’m sure the plants are secure in their identity and familial relationships whether we recognize it or not!
Within the University of North Carolina at Chapel Hill Herbarium (NCU), vascular plants are filed in the cases by family. Within family, alphabetically by genus. Within a genus the plant specimens are filed geographically, then by species. If the family, or genus, or species changes, then the specimen needs to be moved and filed according to those changes.
Usually.
Many botanists recognize the Alliaceae (onion family) and the Trilliaceae (trillium family). However at NCU we file those within the Liliaceae family. We do not deny the existence of the Alliaceae or Trilliaceae – but it would require lots of work to physically shift specimens around, and the shift would be within a few cases that are just a few steps from one another, so it’s just as easy to leave them as is (for now).
Sometimes genera and families are dancing around so rapidly that I figure it’s not worth physically moving specimens, as they’ll be someplace else next year, and yet another place the year after that. Better to stand still, let the nomenclatural dust settle, and re-evaluate in a few years (or decades).
However sometimes, to paraphrase President Thomas Jefferson, in the course of botanical events, it becomes necessary for one genus to dissolve the nomenclatural bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature’s God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation. While I will leave the “reasons for separation” to the taxonomists, let the revolution of re-filing begin!1
In recent years, with increasing frequency, we were having difficulty filing specimens in several families — Orobanchaceae, Plantaginaceae, and Scrophulariaceae — because the family name on a specimen was usually at odds with our filing system.
Historically, NCU recognized the Scrophulariaceae family as being very large – both nomenclaturally and physically. The “Scroph” cases spanned the entire length of the “long” hallway on the 4th floor of Coker Hall. However, for several decades, most botanists have agreed with taxonomist Richard Olmstead and collaborators, “that the traditional Scrophulariaceae are an unnatural assemblage of plants distributed throughout the phylogenetic tree of Lamiales.”1 Analysis of plant DNA and morphological characters place Castilleja (paint brush) and Pedicularis (lousewort) in the Orobanchaceae instead of the Scrophulariaceae. Likewise, Chelone (turtle-heads) and Veronica (speedwells) have joined the Plantaginaceae. An invasive tree that I love to hate, Paulownia (princess tree), has been moved to its own family, Paulowniaceae. One of my favorite plants, Lindernia monticola, has jumped ship from Scroph to its own vessel, Linderniaceae.2
In the spring of 2023 I decided to bust up the Scrophs and get specimens physically filed where users could easily find them. Herbarium undergrad Francisco Puac Vasquez first did a reconnaissance mission to scope out the magnitude of the shifts. He went through all 14 of cases housing Scrophulariaceae and estimated how much space was devoted to each genus. Then I wielded my rainbow of highlighters to color code each genus to its “new” family. As our collection is world-wide in scope there were many genera which I’d never even heard of: Bonnaya, Lamourouxia, and Phtheirospermum among others. For plants growing in North America, I used the family designations in Flora of North America.2 For others I used Plants of the World Online maintained by the Royal Botanic Gardens Kew.3
My goal was to move specimens as efficiently as possible and to avoiding moving specimens multiple times. Along the hallway I deployed multiple carts as temporary homes for specimens on the move. Francisco and I were joined by Bella Nieri, and over the course of a week, the move was accomplished. The final steps were to update the labels on the cases, as well as to update the information in the “Index to Families,” the battery-free, wireless finding aid that resides on a counter near the Herbarium entrance.
I am still getting used to the new geography within the Herbarium. Orobanchaceae formerly occupied less than ¼ of a case in Coker 401 and contained only 4 genera: Conopholis (bear corn), Epifagus (beech drops), Orobanche (broom rape), and Lathraea (toothwort). However, the New Improved Orobanchaceae is also a Much Bigger Orobanchaceae, necessitating its move into the 4th floor hallway to accommodate the 30+ genera spanning 3 ¼ cases. The space in case 223 vacated by Orobanchaceae now houses families Linderniaceae, Mazaceae, Tetrachondraceae, Paulowniacea. The Scrophulariaceae are still in the hallway, but now occupy 1¼ cases instead of 14.
Will I bustin’ up the Liliaceae? Not anytime soon, but I’ll think about it.
With the realization that the nomenclature and arrangement of plant specimens within any herbarium are purely human constructs, I recommend to you “She Unnames Them” by Ursula K. Le Guin, first published on 21 January 1985 in The New Yorker.
SOURCES:
- Disintegration of the Scrophulariaceae. R.G. Olmstead et al., 2001, Am. J. Bot. 88(2): 348-61. https://bsapubs.onlinelibrary.wiley.com/doi/full/10.2307/2657024 accessed on 7 November 2024.
- Flora of North America North of Mexico, volume 17 (Magnoliophyta: Tetrachondraceae to Orobanchaceae). Flora of North America Editorial Committee, ed. Oxford University Press, 2019.
- Plants of the World Online. Royal Botanic Gardens Kew. https://powo.science.kew.org/