Psilonema minutum Schur.
Annual, 5-20 (-25) cm long, erect, spreading or ascending, branched mostly from the base, densely covered with stallate rough hairs. Leaves oblanceolate or linear-lanceolate, 10-30 mm long, 1-5 mm broad, sessile. Racemes 30-40-flowered, ebracteate, up to 10 cm long in fruit. Flowers c. 2 mm across, pale yellow or dull-whitish; pedicel up to 3 mm long in fruit, ascending or horizontal. Sepals c. 1.5 mm long. Petals c. 2.5 mm long, broadest in the middle, apex obscurely emarginate, sparsely hairy at the back, specially on the veins. Stamens c. 1.5:2 mm long; filaments of the outer two smaller stamens with scale-like, notched appendages. Siliculae 2.5-4 mm in diameter, ± orbicular; apex slightly emarginate; style usually c. 0.5 mm long; valves uniformly tumid with a flat narrow margin, glabrous; septum not veined; seeds 2 in each locule, c. 1.5 mm long, ovate-orbicular, very narrowly winged (margined), brown.
Fl. Per.: March-June.
Type: Caucasus, Azerbaijan, Pichler (W, K).
Distribution: S.E. Europe, N. Africa, C. and S.W. Asia to Pakistan and N.W. Himalaya.
A variable species and the status of the var. prostratum Dudley, is not definite. It appears that not only here, but in some other species of Alyssum also, plants become prostrate, reduced with somewhat condensed inflorescence, probably due to dry conditions. I suppose, this variation is not constant, and more of ecological nature than taxonomic.