四数花虎耳草 si shu hua hu er cao

Plants many branched, 2-7 cm tall, with shoots sparsely cespitose. Flowering stem slender, to 1.5 cm, glandular pilose. Shoot leaves opposite, imbricate, obovate-elliptic, ca. 5 × 2.5-3.7 mm, glabrous, chalk glands 3-7, bases connate-perfoliate, apex subobtuse or acute. Cauline leaves 4, opposite, linear, 2.2-3 mm, glandular pilose abaxially proximally and at margin, chalk gland 1, bases free, apex obtuse. Flower solitary, 4-merous; hypanthium glandular pubescent. Sepals broadly ovate, ca. 2 × 2-2.2 mm, abaxially and marginally glandular hairy, veins 3, confluent into a verruca at apex or not, apex obtuse, glabrous. Petals white, obovate, ca. 6.5 × 4-4.5 mm, ca. 11-veined, base gradually narrowed into an indistinct claw, apex obtuse. Carpels connate proximally; ovary semi-inferior; styles ca. 3 mm. Fl. May-Aug.

* Damp rock crevices; ca. 3900 m. S Xizang (Nang Xian).