单窝虎耳草 dan wo hu er cao

Saxifraga lolaensis Harry Smith; S. matta-florida Harry Smith.

Plants many branched, 2.5-4 cm tall, with crowded shoots forming cushions. Flowering stem embedded among rosette leaves and not visible, ca. 1 mm, glabrous. Shoot leaves aggregated into a rosette, ovate, elliptic, or narrowly obovate to subspatulate, abaxially convex, adaxially subconcave, 3-6 × 1-2.5 mm, subleathery, both surfaces glabrous, chalk gland 1, margin ciliate, glandular ciliate on distal leaves, apex obtuse or acute, glabrous. Cauline leaf usually 1, embedded among rosette leaves, suboblong, 3-3.3 × ca. 1 mm, both surfaces glabrous, chalk gland 1, margin glandular ciliate, apex obtuse, glabrous. Flower solitary, sessile; bracts 2, tightly appressed to hypanthium, narrowly ovate, ca. 3.5 × 1.6 mm, subleathery, both surfaces glabrous, chalk gland 1, margin glandular ciliate, apex acute, glabrous. Sepals erect or spreading-erect, ovate to broadly so, 1.5-2.5 × 1.3-2.3 mm, both surfaces glabrous, chalk gland 1, veins 3 or 4, confluent or not at apex, margin glandular ciliate, apex obtuse, glabrous. Petals white, obovate, 3-5 × 1.9-4.5 mm, 3-6-veined, base gradually narrowed into a claw ca. 0.7 mm, apex obtuse. Stamens 2-2.3 mm. Ovary semi-inferior; styles short, thick. Fl. Jun-Aug. 2n = 26.

Alpine meadows, rock crevices; 3900-4800 m. W Sichuan (Daocheng Xian), Xinjiang (Kunlun Shan, Taxkorgan Tajik Zizhixian), S Xizang (Cona Xian, Lhünzê Xian, Mêdog Xian), NW Yunnan (Zhongdian Xian) [Bhutan, Sikkim].

A broad view of the limits of Saxifraga subsessiliflora has been adopted in the present account. While S. lolaensis and S. matta-florida are undoubtedly very closely related to each other and could be regarded as variants of a single species, one of the present authors (Gornall) would like to point out that they differ from S. subsessiliflora in having a triquetrous (vs. flat) leaf apex in which the chalk gland is sunken (vs. submarginal).