Habit of plant, growing in a flat area of serpentine scree on ridge southwest of summit of Black Lassic, Lassics Botanical Area, Six Rivers National Forest, on border of Humboldt & Trinity Counties.

Many thanks to Jane Nelson and Sydney Carothers for help with the ID here. In particular, Sydney checked several voucher specimens from Trinity Co. in the Humboldt State University Herbarium and found that they closely resembled the plants in my photos ''based on annual (appearing) habit, leaf shape, longest filaments fused and with reduced anthers, unlobed stigma, calyx color purple/dark magenta, petal color white with purple midvein, glaucous-green leaves, cauline leaves reduced upwards on the stem, purple underside to basal leaves...''. Sydney also noted that the Lassics Botanical Area plant list presently includes just two Streptanthus species, S. breweri and S. tortuosus, and the plant in my photos is clearly not S. tortuosus (which has longest filaments free).

For a long time I didn't know what to make of this Streptanthus, and I didn't think it was S. breweri, as its habit (esp. lower lvs & branching pattern) appears different from the plant I know by that name from the Clear Creek serpentine area of San Benito county (where I think I recall reading that Brewer first found the taxon and collected the type). But with Sydney's tutelage, and rereading the keys & descriptions I now believe S. breweri is the correct determination.