Diarthron linifolium Turcz.

Herbs annual, erect, 10-40 cm tall. Stem usually single, branched from above base, erect, lower part pale purple, otherwise pale green, terete, slender, glabrous. Leaves alternate, rarely opposite; petiole absent or to 0.6 mm; leaf blade paler abaxially, linear to narrowly lanceolate, 0.7-1.5 × 0.1-0.3 cm, herbaceous, both surfaces glabrous, base cuneate, margin slightly revolute, sometimes sparsely white ciliate, apex obtuse-rounded; midrib conspicuous abaxially, slender, obscure adaxially; lateral veins obscure. Inflorescences terminal, racemose. Pedicel ca. 1 mm, swollen at apex. Calyx green; tube cylindric, 2.2-3 mm, slender, exterior glabrous or sparsely sericeous; lobes 4, erect or slightly spreading, ovate-elliptic, ca. 0.8 mm, apex acuminate. Stamens 4(or 5), inserted above middle of calyx tube; filament short, ca. 0.5 mm; anthers broadly ovate, very small, included within calyx tube. Disk obscure. Ovary ellipsoid, ca. 0.8 mm, glabrous, stipitate; style filiform, 0.8-1 mm; stigma clavate, slightly swollen. Drupe black, ovoid or conic, ca. 2 × 1.1 mm, enclosed in persistent calyx; pericarp membranous, glabrous. Fl. May-Jul, fr. Jun-Aug. 2n = 18.

Gansu, Hebei, Jiangsu (Tongshan), Jilin, Shaanxi, Shanxi, Xinjiang [Mongolia, Russia].

Sandy places; 500-1400 m.

Thesium chanetii H. Léveillé; T. glabrum Schindler.