[Wikipedia] Rarity, Range, Description: Streptanthus insignis is an uncommon species of flowering plant in the mustard family known by the common names plumed jewelflower[1] and San Benito jewelflower. It is endemic to California, where it is known only from the Inner Central Coast Ranges. It grows in grassland and chaparral habitat, usually on serpentine soils. There are two subspecies. The rarer, Arburua Ranch jewelflower (ssp. lyonii), is known from a just few occurrences near Los Banos.[2] This taxon has greenish yellow flowers, sometimes tinged with purple.[3] (link added by Mary Ann Machi)