Alyssum dasycarpum Stephan

Very variable in habit and size of infructescence. Status of the variety nimus Bornm. ex Dudley, with prostrate habit and short spathulate leaves, is not definite, because of many overlapping forms and the variation seems to he continuous and of ecological nature.

Annual, 10-25 cm tall, suberect or spreading, branched, clothed with stellate appressed hairs, and some parts with short and long hairs. Leaves obovate or elliptic, (7-) 10-25 mm long, (2.5-) 4-9 mm broad, sessile, entire, acute. Racemes 15-30-flowered, up to 12 cm long in fruit. Flowers c. 2.5 mm across, pale yellow; pedicel up to 2 mm long in fruit, ascending. Sepals 2-2.5 mm long. Petals 3-3.5 mm long, oblong, apex emarginate, narrowed towards the base. Stamens c. 2.5: 2.8 mm long, filaments not appendaged. Siliculae broadly elliptic, or elliptic-ovate, usually c. 3 mm long, 2.7 mm broad; valves uniformly tumid, with an obscurely flattened margin, pubescent with dimorphic stellate hairs; style (1-) 1.5-2 mm long, tapering, straight with short, subbilobed stigma; seeds 2 in each locule, c. 1.5 mm long, ovate, brown.

Herbs annual, (3-)5-25(-35) cm tall, canescent, with appressed, sessile, 8-14-rayed stellate trichomes, these mixed with longer, simple and forked ones on pedicels, sepals, and fruit. Stems erect, ascending, or decumbent, often several from the base. Cauline leaves subsessile or lowermost attenuate to petiolelike base to 5 mm; leaf blade spatulate, obovate, or oblong-oblanceolate, (0.5-)0.8-2.5(-4) cm × (2-)4-10(-15) mm, gradually smaller upward, base attenuate, apex acute. Fruiting pedicels erect or ascending, (1-)1.3-1.8(-2) mm, subappressed to rachis, stout, straight, covered with stellate trichomes mixed with fewer, simple and forked ones. Sepals lanceolate, 2-3 × 0.8-1.3 mm, persistent till fruit maturity, pubescent as pedicels. Petals pale yellow, spatulate, 2.5-3.5(-3.8) × 0.6-1 mm, glabrous, often persistent, base attenuate, apex deeply emarginate. Filaments 2-2.5 mm, slender, neither appendaged nor toothed; anthers ovate, 0.3-0.4 mm. Ovules 2 per locule. Fruit orbicular or orbicular-elliptic, 2.4-3.5(-4) mm in diam., apex rounded or truncate; valves not veined, uniformly inflated except for a narrow flattened margins, with stellate trichomes mixed with longer, simple and forked ones; style (1-)1.5-2 mm, much broader at base, pilose and stellate at least along proximal half. Seeds usually 2 per locule, ovate, 1.1-1.3 × 0.8-1 mm, slightly compressed, usually not margined. Fl. and fr. Mar-Jun. 2n = 16.

Distribution: Trans-Caspian segim, C. and S.W. Asia, Iran, Afghanistan and Pakistan.

Xinjiang [Afghanistan, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; SW Asia].

Fl. Per.: March-May.

Valleys, steppe, fields; 100-2600 m.

Alyssum dasycarpum var. minus Bornmüller ex T. R. Dudley; A. dasycarpum var. pterospermum Bordzilowski; Psilonema dasycarpum (Stephan ex Willdenow) C. A. Meyer.