31. Sorbus microphylla (Wallich ex J. D. Hooker) Wenzig, Linnaea. 38: 76. 1873.
小叶花楸 xiao ye hua qiu
Pyrus microphylla (Wenzig) Wallich ex J. D. Hooker, Fl. Brit. India 2: 376. 1878.
Shrubs or small trees, 2–5 m tall. Branchlets reddish brown when young, grayish brown when old, terete, puberulous when young, with sparse, oblong or suborbicular lenticels; buds conical or ovoid, 5–7(–8) mm, apex acuminate and puberulous; scales several, reddish brown. Leaves imparipinnate, together with rachis 11–14 cm; petiole 1–1.5 cm; stipules lanceolate or subulate-lanceolate, 4–6 mm, submembranous, margin entire or slightly 2-lobed; rachis slender, adaxially grooved with reddish glands at base of leaflet, ± brown puberulous, glabrous when old, narrowly winged; leaflet blades 10–17(–19) pairs, at intervals of 5–8 mm, pale abaxially, dark green adaxially, linear-oblong, 0.7–1.5(–2) cm × 4–8 mm, both surfaces glabrous, or abaxially with brown hairs only along midvein when young, base obliquely rounded, margin sparsely sharply serrate, apex obtuse or acute. Compound corymbs terminal, 2–4(–6) cm, laxly flowered; rachis and pedicels glabrous, rarely brown puberulous; bracts narrowly lanceolate, smaller than stipules, submembranous. Pedicel 6–9 mm. Flowers 7–10 mm in diam. Hypanthium dark purplish black, broadly campanulate, 2–3 mm, glabrous. Sepals triangular, 1.5–2 mm, apex acute, rarely ± obtuse. Petals pink, suborbicular, 3–4 mm, glabrous, base shortly clawed. Stamens ca. 20, slightly shorter than petals; filaments rose; anthers nearly purplish black. Styles 5, ca. as long as stamens, pubescent basally. Fruit white or flushed pink or crimson, globose or ovoid, 8–10(–12) mm in diam., glabrous, without lenticels, with persistent erect sepals; seeds blackish, oblong-ovoid, 3–4 mm. Fl. May–Jun, fr. Sep–Oct.
Forests or shrubby thickets in valleys or along river banks; 3000--4000 m. E Xizang (Gongbo’gyamda Xian), NW Yunnan [Afghanistan, Bhutan, NE India, N Myanmar, Nepal, Pakistan, Sikkim].
This taxon is probably an aggregate of apomictic microspecies derived partly from Sorbus rufopilosa and, in China, partly from hybrids and back-crosses between the apomictic, tetraploid S. filipes and the diploid S. rehderiana and S. monbeigii.