Lepidium virginicum L.

Family: Brassicaceae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)

Lepidium medium Greene, L. menziesii DC.

Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

Virginia pepperweed

Primary Disseminule Types

seed, fruit segment, fruit

Description (diagnostics are in brown)

Fruit a variably dehiscent 2-chambered silicle with 1 seed per chamber, disk-shaped to elliptic in outline, (2)2.5–3.5(4) mm diameter, strongly compressed perpendicular to the partition, glabrous, ± smooth (not distinctly veined), dull, apically winged, with notch 0.2–0.5 mm deep. Stylar/stigma remnant 0.1–0.2 mm long.

Seed semi-obovate to obovoid (commonly with one side straight) with apex rounded and base tapered, compressed, cross-section narrowly triangular, 1.3–2 mm long x 0.7–1.2 mm wide x 0.2–0.3(0.5) mm thick, unwinged or with a light-colored wing or rim on the curved margin. Surface orangish-brown, shiny (under magnification), minutely papillate, with a longitudinal groove between the radicle and cotyledons on each side of the seed.

Hilar region shallowly notched, with narrow white funicular remnant.

Embryo bent, cotyledons incumbent to obliquely incumbent to accumbent, endosperm lacking.

Similar Species

See Similar Species Comparison Chart and compare to similar Brassicaceae seeds.

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)