Alyssum tortuosum Waldst. & Kit. ex Willd.

The above description is based on non-Chinese material. The Xinjiang plants examined by the present authors are tentatively assigned to this species.

Herbs perennial, cespitose, 6-30(-50) cm tall, often woody at base, canescent throughout, with sessile, 10-18-rayed stellate trichomes. Stems tortuous at base, slender, several from caudex, sterile shoots often absent at flowering. Cauline leaves subsessile; leaf blade narrowly obovate or oblanceolate, 0.5-2(-2.5) cm × 1-3(-5) mm, gradually smaller upward, base attenuate, apex acute to subacuminate. Racemes corymbose, in a panicle terminating each stem. Fruiting pedicels divaricate or rarely ascending, (2-)3-6(-8) mm, slender, straight or slightly curved upward, uniformly stellate. Sepals oblong, 1.2-1.8 × 0.5-0.6 mm, deciduous, stellate. Petals yellow, spatulate, 1.5-3 × 0.7-1 mm, glabrous or stellate outside, caducous, base attenuate, apex often obtuse or rounded. Filaments 1-1.5 mm; median pairs unilaterally broadly winged, apically 1- or 2-toothed; lateral pair with a lanceolate basal appendage apically acute; anthers ovate, 0.2-0.3 mm. Ovules 1(or 2) per locule. Fruit elliptic to elliptic-obovate, 2.5-4(-4.5) × (1.5-)1.8-2.5 mm, apex obtuse to subacute; valves not veined, often asymmetrically inflated on 1 side, flattened on other, densely covered with stellate trichomes; style 0.5-1.5 mm, slender, glabrous or sparsely with stellate trichomes basally. Seeds 1(or 2) per locule, ovate, 1.1-1.4 × 0.8-1.1 mm, compressed, not margined. 2n = 16, 32.

Xinjiang [Kazakhstan, Russia, Turkmenistan; SW Asia, Europe].

Alyssum alpestre Linnaeus var. tortuosum (Willdenow) Fenzl.