Sidalcea of Marin County

by Doreen Smith

Several of our native mallows flower in May or later. Most of us are familiar with the commonest perennial species, Sidalcea malviflora ssp. malviflora, but may not have recently checked to find we are supposed to have three or more subspecies according to Jepson Manual # 2 and their online eFlora website ( Two other perennial species are less common and are listed rare; they are Sidalcea calycosa ssp. rhizomata of Pt. Reyes and Sidalcea hickmanii ssp. viridis, a serpentinite endemic of Carson Ridge. There have been no reports of anyone seeing the latter for many years. We have a photograph of ssp. anomala from San Luis Obispo County. It is grown in East Bay Parks’ Tilden Botanic garden and differs in having cut leaves and not round ones like ssp. viridis.
We have two annual Sidalcea species: Sidalcea diploscypha, which can be seen in serpentine grassland such as at Big Rock by the Loma Alta trail and The seasonal wetland species Sidalcea calycosa ssp. calycosa, which is unusual in Marin and found accessible only near the MMWD Sky Oaks Bon Tempe reservoir’s southeast end pump outlet.

Photos by Vernon Smith