by Andrea Williams
As the new vegetation ecologist for the Water District, I recently had the opportunity to rediscover two plant species not noted on the watershed for over 50 years.
Mount Tamalpais is an exceptionally well-traveled place, and noted botanists have combed its slopes and marveled at the plants found here for over a century. The Marin Flora, a list of all the plants found in the county with descriptions, was originally released in 1949 and updated most recently in 2007. Its original author, John Thomas Howell, described hundreds of plants with their locations as “Mount Tamalpais.” One of the plants he noted was named for him: Howell’s quillwort (Isoetes howellii). I encountered this plant last month along the drying lakeshore with a California Native Plant Society group; the hike leader said it hadn’t been noted for decades here. It’s easy to see why: quillworts look like low tufts of green grass. They’re related to ferns in that they produce spores—not flowers—but their spores are hidden in the bases of their leaves. Thus they are easily overlooked.
The second plant also looks like a grass, because it is one. Knotroot bristlegrass (Setaria gracilis) was noted by Howell around Phoenix Lake, but hadn’t made it on to the list of plants found on the watershed. I saw a plant I didn’t recognize in our parking lot at the ranger station, which turned out to be knotroot bristlegrass. I went down to Phoenix Lake and wouldn’t you know, right by the plaque, there it was—maybe the same stand noted 60 years ago!
While I’d love to find a plant here that no one’s found before, the joy of discovery isn’t lessened by becoming rediscovery. It places my work in the context of what was here 100 years ago, when Willis Linn Jepson made his notes, or 60 years ago when J.T. Howell was at work on the Flora. It exhorts me to keep detailed notes, so in another 10 or 50 or 100 years someone else can look back with their own rediscovery.