Western bog yellow-cress is an erect-stemmed and nearly glabrous annual, biennial or short-lived perennial growing from 12" to over 2' tall.  The lower leaves are 3"-5-1/2" long, lyrate-pinnatifid and wing-petioled, while the upper cauline leaves are shorter, nearly sessile and dentate or somewhat lobed.  Each inflorescence is a long raceme with slender spreading to ascending pedicels, and the individual flowers are tiny with yellow widely spoon-shaped petals.  This cress bears thickish oblong to linear, straight or slightly curved siliques 1/4" to 1/2" long containing brown seeds.  As its name suggests, it is found as part of several plant communities in wet depressions, stream beds or sand bars up to about 6000' in elevation throughout California, blooming from April to July.  These pictures were taken at the edge of the drying bottom of Rocky Oaks pond in the Santa Monica Mountains.

Click here for Latin name derivations: 1) Rorippa 2) palustris 3) occidentalis.
Pronunciation: roar-IP-pa pal-US-tris ok-si-den-TAY-lis.
Click here for Botanical Term Meanings.