by Andrea Williams, Vegetation Ecologist
This is installment 11 of a 12-part series on grasses. Read the previous installment here.
I feel this post is a bit of a cheat, just so you know. It’s not about any one grass, or a genus, but about the thing even plant lovers seem to fear: grass identification.
This past week I helped teach a half-day workshop titled “Grass ID: You can totally do this!” before the California Native Plant Society’s Conservation Conference. Almost everyone in the class had used the Jepson Manual or some other dichotomous key to identify plants, but somehow grasses were planta non grata
. There’s a barrier to plant lovers tackling this important and diverse segment of the flora.
|Phyllostachys aurea (the one with the stems). Photo by Kurt Stuber.
Perhaps it is the specific terminology that causes such consternation, or the tiny parts, or the six-page key to the genera. But the thing is, there’s no perfect or right answer to worry about, no three-guess limit. There’s just getting comfortable ascribing a name to the thing you’re looking at. And once you figure out what the people who wrote the key are talking about, it’s not too hard to get to comfortable (once you give up the idea of getting to “right”).
|Poa bulbosa and Cenchrus (the ones with the fruits). Photos by Zoya Akulova.
Sometimes my friend will ask me, “Hey what’s that movie with that guy?” and I will answer, “The one with the teeth or the one with the hair?” because an absurdly vague question deserves a pointed focusing answer. So it is with keying grasses. If you come to the key with “Hey what’s this grass?” as your question, you will get “The one with the stems or the one with the fruits?” as your answer. Understanding how keys are written allows you to navigate them with increasing ease.
Very often, a taxonomist will write a key with all the species in front of her; the likelihood of your encountering a Sierran meadow endemic on Mt. Tam are slim, but you will encounter it in the key. So keying can sometimes feel frustrating, having to weigh and consider and wade through dozens or hundreds of extraneous grasses.
Much like I now turn to the Internet Movie Database to help answer “Hey what’s that movie with that guy?” I often look at Calflora
to help answer “Hey what’s this grass?” I can search by location and family or genus, and narrow my choices down to dozens instead of hundreds. If I recognize similarities to other grasses, I can make a much more educated guess. Then I can read the description in the key, and if I feel comfortable that my grass fits the description, I’m done—and if not, I can just keep trying!