Medicago polymorpha L.
Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)
Medicago nigra (L.) Krock., M. hispida Gaertn.
Pertinent Common Names (particularly those used in California; go to GRIN for other common names)
Primary Disseminule Types
fruit (not likely to be directly dispersed to grape bunches), seed
Description (diagnostics are in brown)
Fruit a pod with few seeds, dehiscence variable, tightly coiled 2–6 times, 4–6 mm diameter (excluding spines), brown at maturity, glabrous, surface reticulately veined, otherwise smooth or with 2–3 rows of tubercles or spines.
Seed reniform in outline with a distinct peripheral notch midway along one of the long faces and a prominent darkened bump (“lens”) between notch and end of seed (i.e., over cotyledons), somewhat compressed, cross-section ovate, usually twisted along long axis (commonly the radicle and lens appear to be out of line with one another), shallow whitish grooves on either face of the seed sometimes mark the separation of radicle from cotyledons, (2.2)2.5–3.5 mm long x 1.3–1.9 mm wide x 0.6–1 mm thick. Surface dull, smooth (finely textured under magnification), yellowish-brown to terra cotta, solid to mottled.
Hilum in notch, round, ca. 0.1 mm diameter, whitish with a slit-like opening near its center.
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)
AUQP, NZBORIC, NZBPI