This month I have a flower request from the folks at the plant sale. Yellow-eyed grass is one of the two common species of Sisyrinchium native to Western Washington. It ranges mostly along the western slope of the Cascades from BC South through California. A lover of damp places, it can be found at the edges of wetlands, along seeps, and in wet meadows.
Sisyrinchiums are members of the iris family. The name comes from Theophrastus, although the modern usage applies to a New World genus. Sisyrinchium have their center of diversity in Argentina, and genetic evidence seems to point to two separate waves of expansion into North America. Sisyrinchium idahoense (blue-eyed grass), our other common Sisyrinchium here in Western Washington, comes from a different branch of the genus than californicum does. There are also a couple of endemic Sisyrinchiums in the state that may have speciated from the more common varieties during an ice age.
In the garden, it is a short-lived perennial that re-seeds in damp spots (like the well-watered beds in the nursery). Usually less than a foot tall, the symmetrical yellow flowers that peek out between the strap-shaped leaves open on sunny mornings and often close by afternoon. When not in bloom, it forms pleasing clumps of pale green mini-iris. The dry leaves turn a purplish black, providing a nice contrast.
Bibliography:
Lisa Karst, Ph.D. Phylogeny, Character Evolution, and Biogeography of Sisyrinchium (Iridaceae)
http://www.duke.edu/~lk38/