Ranunculus trigonus Hand.-Mazz.

The authors have seen no material of Ranunculus shuichengensis L. Liao (Acta Phytotax. Sin. 35: 57. 1997), described from Guizhou, but the protologue suggested that it is very closely related to R. trigonus . It was distinguished by the more broadly obovate petals, 5–6 × 4–5 mm, more compressed, narrowly marginate, suborbicular achenes, and the crenate-serrate leaf margins.

Herbs perennial. Roots fibrous, subequally thick. Stems 4.5--48 cm, spreading brownish pubescent, sometimes appressed pubescent above or strigose, usually branched. Basal leaves 3--6; petiole 1.4--18 cm, spreading pubescent or strigose; blade simple, rarely ternate, 3-partite or 3-sect, pentagonal or broadly ovate, 1.2--4.5(--5) × 1.5--4.6(--6) cm, papery, strigose, base subtruncate or cordate-truncate, central segment rhombic-cuneate or rhombic-obovate, 3-lobed, incised-dentate; lateral lobes rhombic-cuneate or rhombic-obovate, 3-lobed, incised-dentate; lateral segments oblique rhombic or oblique flabellate, unequally 2-cleft; central leaflet of ternate leaves broadly rhombic, 3-partite, petiolulate; lateral leaflets unequally 2-partite, petiolulate. Lower stem leaves similar to basal ones; upper stem leaves 3-sect. Monochasium terminal, 2- or 3-flowered; bracts leaflike. Flowers 0.6--1(--1.5) cm in diam. Pedicel 0.5--6 cm, densely appressed puberulent. Receptacle puberulent. Sepals 5, ovate or oblong, 4--5 mm, abaxially pubescent. Petals (3--)5, oblong or obovate-oblong, 3.2--6(--8) × 1.6--4 mm, nectary pit covered by a scale, apex rounded. Stamens numerous; anthers oblong. Aggregate fruit subglobose, 4.5--7 mm in diam.; carpels numerous. Achene flat, obliquely broadly obovate, 2--3.5 × 1.8--2.8 mm, glabrous, narrowly marginate; style persistent, 0.5--0.8 mm. Fl. Mar--Sep.

SW Sichuan, SE Xizang, Yunnan.

* 1300--3300 m.