by Andrea Williams
This is installment four of a 12-part series on grasses. Read the previous installment here.
I’m sure you’ve heard the phrase “sowing your wild oats,” but did you know that California wild oats (aka California oatgrass, Danthonia californica) is the grass that loves you back? And they have a secret seed to sow?
I grew to know California oatgrass in Oregon, when I spent my summers on a coastal grassland studying the habitat of the threatened Oregon silverspot butterfly. At first I just liked how obvious it was, three fat spikelets and a little eyelash winking at you where the grass blade met the stem. It wasn’t until my time at Redwood National and State Parks that I appreciated the ingenious strategy this grass employs in reproduction. And it wasn’t until last month that I fully appreciated just how hardy and long-lived California wild oats can be.
Most grasses, California oatgrass included, reproduce through wind-pollinated flowers that turn into seeds; think wheat or rice grains. But oats, California oatgrass included, are tasty and can be browsed down before they have a chance to become a new plant. California oatgrass has a contingency set of seeds in the base of its flowering stalk. These flowers are cleistogamous, meaning—like nuns in a cloister—they are kept shut away. The flowers self-pollinate inside the stem, and when the upper (chasmogamous, opening, like a yawning chasm) wind-pollinated flowers have ripened into seeds and are ready to drop, the stem itself detaches from the basal clump of leaves. This gave rise to a new dance, the “Danthonia Shuffle,” during a native grass seed gathering expedition. Rather than plucking individual seed heads, you can shuffle your feet through an oatgrass-laden path and once a sufficient number of stems have gathered around your shins, just scoop the whole lot up into a bag! You not only have the seeds that haven’t dropped from the seed heads, but you have the straw and the secret seeds as well!
California oatgrass, once established, is a hardy and forgiving plant that tolerates mowing well. It does prefer wetter areas in grasslands, where it mixes with purple needlegrass, blue-eyed grass, and the cheery yellow of California buttercups. On Mt. Tamalpais, our oatgrass tends to have three to five spikelets above a clump of slightly greyish green leaves. On the coast, plants tend to be a little greener. Last month, as I was staffing the California Native Grassland Association booth at the Point Molate Beach opening, I looked down at the mowed-and-trampled ground and saw a little oatgrass eyelash winking up at me from an emerald clump of leaves—California oatgrass had survived decades of people walking and mowing and picnicking and parking on it.
And why is it the grass that loves you back? The arrangement of spikelets matches the hand symbol for “I love you” in sign language.