Saxifraga unguiculata Engl.

The Saxifraga unguiculata / S. vilmoriniana complex requires further examination. The chief distinctions between the two taxa are supposed to lie in plant height, cauline leaf shape, and petal base shape. Plant height varies enormously and cannot be used to distinguish the taxa. Similarly, cauline leaf shape is variable, and the distinction is at best subtle: oblong in S. unguiculata but narrowly linear in S. vilmoriniana, according to Engler and Irmscher (in Engler, Pflanzenr. 67(IV. 117. I): 142, 149. 1916). The difference in petal base shape is perhaps worthy of more consideration: abruptly contracted into a claw in S. unguiculata but cuneate in S. vilmoriniana. However, the occurrence of intermediates makes even this distinction unclear and, in one of the syntype collections of S. vilmoriniana (Pratt 575, BM, E, GH, K), the petals are basally contracted into a claw. The two taxa are united in the present account because a satisfactory key to distinguish them could not be written. It should also be noted that S. unguiculata var. limprichtii may deserve recognition as a distinct species because of the differences in basal leaf morphology, usually fewer flowers, and associated, distinct geographical distribution.

Herbs perennial, cespitose, 2.5-13.5 cm tall. Shoots branched, with leaf rosettes. Flowering stem leafy, proximally glabrous, distally brown glandular pilose. Rosette leaves spatulate to narrowly subobovate, 4.5-8 × ca. 1.5 mm, subcarnose, both surfaces usually glabrous, margin setose-ciliate or glabrous, apex mucronate. Cauline leaves remote, oblong or lanceolate to ensiform, 4.4-15 × 1-2.3 mm, carnose, both surfaces usually glabrous, rarely sparsely glandular hairy abaxially, margin glandular or eglandular ciliate, apex mucronate. Flower solitary, or cyme corymbose, 2-8-flowered, 2-6 cm; pedicels slender, 0.3-3 cm, brown glandular hairy. Sepals erect, then spreading to reflexed, ovate to narrowly so, 1.5-3 × 1-2.1 mm, carnose, abaxially brown glandular hairy, adaxially glabrous, veins 3-5, not, partly, or fully confluent at apex, margin glabrous or ± glandular ciliate, apex obtuse or acute. Petals yellow, proximally orange spotted, narrowly ovate, subelliptic, or oblong to lanceolate, 4.5-7.5 × 1.5-2.9 mm, 1- or 2-callose near base, sometimes obscurely so, or not callose, 3-7-veined, base with a claw 0.1-1 mm, apex subobtuse or acute. Stamens 2.8-4.3 mm. Ovary subsuperior, broadly ovoid, 2.3-3.8 mm; styles 0.5-2 mm. Fl. and fr. Jul-Sep.

S Gansu, WC Hebei, Qinghai, Nei Mongol, Ningxia, N Shanxi, W Sichuan, Xizang, NW Yunnan.

* Forests, scrub, alpine meadows, rock crevices; 1800-5600 m.