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'Andrea Williams'

Jan 22

Change Is Hard

Posted to MMWD Blog: Think Blue Marin on January 22, 2015 at 3:43 PM by Ann Vallee

by Andrea Williams, Vegetation Ecologist

This is installment 10 of a 12-part series on grasses. Read the previous installment here.

I thought it fitting to write about vanilla grass (Hierochloe occidentalis; Hiero = “sacred” chloe = “grass”) during the holidays, but it no longer exists. Now it’s lumped into Anthoxanthum (Antho = “flower” xanthum = “yellow”). We have traded a sacred grass during the holy days for yellow flowers and vacations. Not that I mind a little time off, but sometimes change is hard, even if it is for good reason.

Anthoxanthum occidentale

 Anthoxanthum odoratum
The new Jepson Manual is not so new; eventually we botanists will just call it the Second Edition. But even though it came out three years ago (!), some of the name changes still rankle. The loss of Hierochloe as a genus name is one of those. This sweet-smelling grass has been used by tribes as incense, and has a history of being scattered in churches for its fragrance. But, I suppose, a grass by any other name smells as sweet?

Vanilla grass smells much like sweet vernal grass (Anthoxanthum odoratum), its new genus-mate. There the resemblance ends. Vanilla grass grows in broad-leaved clumps, its open-branched inflorescence of oval spikelets pearly above emerald. Sweet vernal grass seems green only briefly, single flowering stalks sharp, dense, straw-colored spikes. Even the taxonomists acknowledge the oddity: The genus description includes the following disclaimer: “As treated here, the genus including Hierochloe, which is readily distinguishable in North America, but not in Asia and southern hemisphere.”

We have both vanilla grass and sweet vernal grass on Mt. Tam; the best stands of vanilla grass are at the western end of Kent Lake and the eastern end of Phoenix, although it can be found in many forested areas throughout the watershed. Vanilla grass is one of the first plants to bloom, often flowering in January. Sweet vernal grass, an invasive non-native, is limited to Sky Oaks Meadow at present.

Taxonomy today includes more and more genetic work, instead of relying on appearances and visual distinctions. While the new arrangements reveal a deeper knowledge of lineages and relationships between different kinds of plants, a feeling that someone reordered the world persists. Our relation with things is so reliant on language, and the name is part of our conception of it. The idea that knowing the “true name” of a thing gives you power over it goes back ages in human history. Part of me thinks of molecular taxonomy (grouping by DNA-based relationships) as an almost mystical pursuit, a laborious study to reveal the true nature of things. And even though Arthur C. Clarke postulated that “Any sufficiently advanced technology is indistinguishable from magic,” it still makes me cranky.

Jan 22

You Can Totally Do This!

Posted to MMWD Blog: Think Blue Marin on January 22, 2015 at 3:40 PM by Ann Vallee

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
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
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!
Nov 14


Posted to MMWD Blog: Think Blue Marin on November 14, 2014 at 3:58 PM by Ann Vallee

by Andrea Williams, Vegetation Ecologist

This is installment nine of a 12-part series on grasses. Read the previous installment here.

I wrote earlier this year about how I thought fescues (Festuca sp.) were the best. And I do still believe that, but I also admit a growing fondness for the bromes (Bromus sp.) as well—a budding bromance, if you will.

For one thing, they have a couple of key features that make them quite recognizeable: downward-pointing hairs on the lower part of the stem, and distinctive multi-flowered spikelets arranged in a branching pattern called a panicle. And then, even though it is a large genus—we have nine or 10 species on the mountain—you really only need to know three more things about it to get to species: whether it is an annual or perennial, how flattened the spikelets are, and how long the awns are.
California brome 
 California brome (Bromus carinatus)

While we have around 10 species on the watershed, only two are native. This is the best time of year to tell our natives from the non-natives: Since the natives are perennial and the non-natives are annual, you can tell the natives by their remaining flower stalks and loose clump of green leaves at the base. The non-natives, if you see them at all, will be dead bleached husks with no green. Bromes, like many grasses, “shatter above the glumes,” which means when their seeds fall the lowest set of bracts (called glumes) stay on the flowering stalk. This is similar to oaks, where some species’ acorn caps stay on the tree instead of with the acorn. The height (3-4’) and pattern of the flowering stalks with glumes mean you can tell our native bromes apart even in winter—that, and their different habitats. California brome (Bromus carinatus) prefers open, sunny grasslands with its open, shiny panicle of flattened spikelets; forest brome (B. laevipes) usually grows in, well, forests and has a closed, drooping panicle of fuzzy fat spikelets.

Unlike fescues, our native bromes are rarely dominant where found. Rather, they are sprinkled across the landscape like fine spices. Some of the non-natives, though, are known for taking over entire ecosystems in certain areas. Cheat grass (B. tectorum) is sometimes titled “The grass that ate the West” for its predominance in the intermountain west sagebrush-juniper scrublands. These areas rely on infrequent fire (every decade or two) to keep the sagebrush-juniper balance, but once cheat grass comes in fires often happen every year: The cheat grass is annual, and produces enough fine, “flashy” fuels to carry fire that often; too-frequent fires kill sage and juniper, promote more cheat grass, and the problem grows ever larger. Our cheat grass “problem” is limited to a few plants occasionally showing up at Peters Dam or the south side of Mt. Tam. We have much more downy brome (B. hordeaceous), ripgut brome (B. diandrus), and red brome (B. rubens), none of which begin to reach the level of worrisome monoculture—we leave that to brooms, not bromes!