Here is the first of two or three iris galleries I’ll post through the spring, this for Inverness Ridge. Later, I may do a purely coastal one, and in a few weeks another, for the resplendent variety of color and form that will be exploding inland.
Iris is Greek for rainbow. Of the 300 kinds of iris in Old World and New, none is more a rainbow than Iris douglasiana—every color in the genus displays itself in this single species. Even better, Marin’s inland populations of Douglas Iris are by far the most rainbow-like of any from its range, Santa Barbara northward to central Oregon. The Douglas Iris of the Marin Peninsula (not including Point Reyes) have even been honored with their own name: Marin Iris.
Why the rainbow locally? Until suburbanization, Marin’s forests and woodlands were a biological island, cut off northward by broad grasslands that stretched into Sonoma. (Did you know we even had our own unique subspecies of chickadee, now swamped and lost in just a few decades as chickadees from the north colonized tree plantings southward?)
Botanists think Marin Iris are a ‘hybrid swarm,’ mostly Doug Iris, like the ones in this gallery from Inverness Ridge, but with abundant genes from Grass Iris (Iris macrosiphon), and, in central Marin, from another species now, curiously, found only far north and east of us, Iris fernaldii. Not much influenced genetically by the swarm, Douglas Iris on the headlands and the Point Reyes coastal plain are nearly uniform deep purples and blues.
Iris terminology: The three upright petals, called the standards, are actually the flower’s three petals. The three falls—usually marked with lovely white or black venation as a signal to pollinators—are the flower’s sepals, and not petals at all.