Vella tenuissima Pallas, Reise Russ. Reich. 3: 740. 1776; Bunias tatarica Willdenow; Euclidium tataricum (Willdenow) de Candolle; E. tenuissimum (Willdenow) B. Fedtschenko; Litwinowia tatarica (Willdenow) Woronow.

Herbs annual, (7-)15-40(-51) cm tall, hirsute with spreading, straight simple trichomes to 1.5 mm. Stems often with ascending slender branches mostly above middle. Basal and lower cauline leaves with petioles (0.2-)0.5-1.5(-2) cm; leaf blade narrowly oblong or linear-oblanceolate, (0.6-)1-5(-7) × (0.3-)0.5-1.5 cm, sparsely pubescent with simple trichomes and fewer stalked glands 0.05-0.15 mm, base attenuate, sinuate-dentate or pinnatifid; lateral lobes 3 or 4, much larger terminal one, apex acute or obtuse. Middle and upper cauline leaves sessile or shortly petiolate, linear, linear-lanceolate, or linear-oblong, base attenuate, margin entire or rarely denticulate. Fruiting pedicels 0.1-0.6(-1) mm, slender, readily detached from their articulation with rachis, ascending. Sepals 1.5-2 × 0.4-0.6 mm, glabrous or subapically sparsely pubescent. Petals white or purplish, narrowly spatulate or oblong, 2-3(-3.5) × 0.3-0.6(-0.9) mm, apex obtuse; claw to 1.5 mm. Filaments 1.5-2.5 mm; anthers 0.2-0.4 mm. Fruit globose, (1.7-)2-2.5(-3) mm in diam., erect, 2-seeded, minutely papillate, terete; replum expanded and to 1.5 mm wide basally, narrowed to apex; style cylindric, (1.5-)2-2.8(-3.5) mm, straight. Seeds yellow, orbicular, (1-)1.2-1.4 mm in diam. Fl. and fr. Apr-Jun. 2n = 14.

Roadsides, pastures, fields; 300-3500 m. Xinjiang [Afghanistan, India, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; SW Asia].