Distribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America.
Habitat: Disturbed areas, such as overgrazed land and waste areas, usually where dry.
Flowers: March-June
Origin: Introduced from Eurasia
Conservation Status: Not of concern
Annual herb with simple or branched stems 20-60 cm tall.
Alternate; lower leaves deeply pinnately dissected or compound; upper leaves simple and strongly clasping the stem.
Yellow, small, with 4 petals; in elongate racemes at ends of stems.
Small ovate capsules (silicles) to 4 mm long.
Look for the dissected lower leaves, strongly clasping (seemingly perfoliate) upper leaves, small yellow flowers with 4 petals, and small ovate silicles.
PNW Herbaria: Specimen records of Lepidium perfoliatum in the Consortium of Pacific Northwest Herbaria database.
WA Flora Checklist: Lepidium perfoliatum checklist entry.
E-Flora BC: Lepidium perfoliatum atlas page.
CalPhotos: Lepidium perfoliatum photos.
USDA Plants: Lepidium perfoliatum information.