Sisymbrium altissimum

Sisymbrium altissimum L.
Family: Brassicaceae

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

Norta altissima (L.) Britt.

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

tall tumble mustard

Primary Disseminule Type

seed

Description (diagnostics are in brown)

Fruit a many-seeded, dehiscent silique, linear-cylindric, straight, rigid, glabrous, (4)5–10(12) cm long x 1–2 mm wide, without conspicuous beak.

Seed oblong in outline with ± truncate ends, somewhat compressed, cross-section ovoid or bilobed, one face longitudinally convex, the other flat to sometimes transversely convex, 0.8–1.1 mm long x 0.5–0.6 mm wide x ca. 0.5 mm thick, with a distinct longitudinal groove on both faces delineating the radicle from the cotyledons (sometimes a second groove is seen on one of the faces). Surface glabrous, variable in texture, rough, with a greasy appearance, yellowish-brown to dull pale orange with a slightly darker hilar end, often with dark green or purplish lines or speckles.

Hilum in a notch, white funiculus often present.

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

Similar Species

See Similar Species Comparison Chart and compare to seeds of Lepidium.

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

Seeds. Note the greasy
appearance of the
seed's surface.
Photo: J. O'Brien, © 2007,
The Regents of the University
of California

Seeds with hilar region at bottom. Longitudinal grooves mark the division between the radicle and the cotyledons on each seed.

Three more seeds. On the third seed, note the greenish markings as well as the transverse ridge
on one of the two faces.

Looking down, at a slight angle, on the hilar region of four seeds. On each seed, the larger of the two lobes is where the cotyledons lie and the smaller lobe represents the position of the radicle.