Although nearly half a century old, Newcomb’s excellent wildflower guide is still in print and still in use. Over the decades since 1977—or rather since 1950, as I’ll explain—the classification and naming of plants keeps changing at what seems an ever-accelerating pace. I know of two existing attempts to compile a list of changes to the scientific names in Newcomb’s. Steve Young created one in 2007–10; the other, though undated, can’t be much newer. It’s time for another one, and this time, linked to the iNaturalist database.
Newcomb’s guidebook is something like a beginner-friendly, geographically-restricted abridgement of Gray’s Manual of Botany, 8th edition, edited by M. L. Fernald in 1950. Newcomb created his rightly-famous key system and with it, organized species selected from Gray’s, writing simplified, much-less-technical descriptions. Whenever Fernald described multiple varieties of a species, Newcomb wrote his description so that it could cover all of them (all that were relevant to his chosen geographic area, that is), but without explicitly saying that that’s what he was doing. He declined to make any changes or updates, however minor, to the material in Gray’s. It may seem perverse of him to ignore a quarter century of progress, but this decision has the great advantage that Gray’s now serves as a technical companion to Newcomb’s. If anyone should find the species information in the latter too selective or too vague, they can seek out the detailed version, which in turn can be a bridge to more modern literature.
That’s what I did in the present project. A certain amount of guesswork was needed, in a few cases, in order to figure out which of Fernald’s varieties Newcomb had included. I then researched how taxonomic opinions have shifted since 1950. Though there are a number of names altered simply to adhere to the International Code of Botanical Nomenclature, or to correct an error, or to be consistent with a new identification of a type specimen, in most cases changes of names reflect splitting or merging of genera, elevation of varieties to species or the reverse, or the entire abandonment of distinction between certain species. New understanding of relationships shifted a few species from one genus to another, such as when the former Armoracia aquatica was found to be more closely related to Rorippa sylvestris than to Armoracia rusticana. There are even a few complicated instances of species boundaries being redrawn in new places that expand in one respect and contract in another (for example, the revised understanding of Euphorbia maculata, which you can research for yourself if you want your head to ache). Alan Weakley’s Flora of the Southeastern United States was immensely helpful since he has provided a detailed account of synonyms for all his taxa, and only a minority of Newcomb’s species are too northern to be included in his work.
GUIDELINES AND PROBLEMS
In my opinion, in order to be a true update to Newcomb’s work, a list of name changes should follow the same principles of simplification as the original author did: he made almost no reference to infraspecific taxa, and neither should the update list; he omitted species that he thought too obscure or too difficult to identify, and the update list shouldn’t introduce any that he would have preferred to omit. I’ve found that it’s impossible to follow these idealized principles entirely, but they provide useful guidelines. Do you agree?
Without regrets, I can partly abandon the principle of never mentioning subtaxa, and it’s not too difficult to decide when they are absolutely needed. One instance is when two of Newcomb’s species have been reduced to varieties or subspecies but are too distinct to be easily combined into a single guidebook entry, as with Antennaria howellii ssp. canadensis and ssp. neodioica (these two subspecies can be described tidily, but A. howellii as a whole only by a suite of partially-concurring characters) or Solidago uliginosa var. uliginosa and var. peracuta (there is an eye-catching difference between them that places them on separate pages in Newcomb’s). Another is cases like that of Newcomb’s Silphium trifoliatus; although what Fernald called Silphium asteriscus is found within the guide’s region, Newcomb didn’t choose to mention it, so that now, when those two species have become S. asteriscus var. trifoliatus and var. asteriscus, the description in the guide conspicuously refers to only the first variety, excluding the second which lacks leaves in whorls of 3.
The other principle, which becomes an issue every time one of Newcomb’s species is subdivided, is a tricky one. Just what, exactly, is too obscure to be mentioned? I don’t trust my own judgment. Yes, I don’t see a problem with not mentioning Rumex maritimus which, according to FNA and BONAP, has only been observed as a “casual alien” at a couple of locations in Massachusetts and New Jersey. But I’m genuinely uncertain about Oenothera biennis ; O. biennis is far commoner than the species split from it, O. villosa and O. nutans , but is it enough commoner? I also don’t know what to say in cases where neither part of a subdivided species is rare, but they’re extremely difficult for a casual observer to tell apart: see, for example, Humulus lupulus .
I’d like to draw attention to the confusion surrounding Thymus serpyllum , where I’m pretty certain that the text, adapted from Fernald, describes a different species than the one depicted in the illustration, drawn from a New England plant. And when you read my epic-length comment on Atriplex patula , you’ll see why after two days of research, I wanted to throw up my hands and tell updaters, “Just cross out this entry in your Newcomb’s because it needs to be completely rewritten.”
I’ve colored some lines in the document PINK; those are ones that leave me with uncertainty or a serious dilemma.
With that, I toss the ball to you, field guide fans of iNat. Please read, comment on and contribute to my research document, and tell me what sort of update list you would like to have. A link to Google Docs is provided above (if you can’t or won’t use Google Docs, what file sharing method do you prefer?) I hope the columns are sufficiently self-explanatory. GREY cells in the table represent material added for context but not present in Newcomb’s.