Like a handful of precious jewels scattered on a rocky slope, this flower is easily missed but well worth a closer look. With single flowers spread out on a long, leafless stalk they can blend into the background. Each blossom is gathered at the base into a balloon that reminds me of the bell-shaped skirts at an old-fashioned ball. At the mouth, the four petals crinkle and flare outwards from a purple-tinged mouth. This is Streptanthus glandulosus ssp. Secundus. The ssp means “subspecies” – a lot of times this designation refers to very subtle differences within a species that a casual botanist isn’t interested in. But in this case, it means this flower is white while the others are dark purple. There are several different jewelflowers in the area, distinguished by their distinctive pouchlike shape, but this is the only white one listed in the Marin Flora.
Jewelflowers are in the same family (Brassicaceae) as the common wild mustards and radish weeds that grow all over, but their signature blossoms are different from most members of this group, which have simple four-petalled flowers. Milkmaids are a good example of a classic brassica.
Flowers Of Marin 