Sorbus insignis (Hook. f.) Hedl., Kongl. Svenska Vetenskapsakad. Handl. 35(1): 32. 1901.

Li, Meng, Sylvester, Steven P., Wang, Zhang-Pei, Pei, Yi-Da, Gao, Xin-Fen, Zhao, Yuan & Jiang, Wen-Qi, 2020, Re-instatement of Sorbus harrowiana (Rosaceae), based on morphometric analysis, PhytoKeys 166, pp. 29-39 : 29

Sorbus insignis (Hook. f.) Hedl., Kongl. Svenska Vetenskapsakad. Handl. 35(1): 32. 1901.

≡ Pyrus insignis Hook. f., Fl. Brit. India 2(5): 377. 1878.

Type.

India. Sikkim: 8000-11000 ft [2438-3353 m alt.], J.D. Hooker & C.B. Clarke s.n. (holotype: K (K000758177 [image!])). Fig. 2A .

Description.

Trees or shrubs. Stems greyish-brown; bark grey; branchlets greyish-brown when old; rusty brown tomentose when young, glabrous when old; winter buds narrowly ovoid, 1.0-1.8 cm long, scales initially puberulent, glabrate later; apex shortly acuminate or acute, brownish. Leaves pinnately compound, 15-20 cm long; stipules persistent, suborbicular, sometimes lobed, 1-2 cm wide, margin entire or serrate with pointed teeth; petiole 1.7-4.0 cm long, glabrous; rachis sparsely tomentose, glabrous when old; leaflets 7-16, at intervals of 1-2 cm long, oblong or oblong-lanceolate, 5-8 × 1.5-2.0 cm, l/w ratio 3.2-4.2, middle leaflets l/w ratio 3.3-4.0, lateral veins 24-30 pairs, margin slightly revolute and shallowly crenate, base rounded or obliquely cordate, apex obtuse, both surfaces tomentose when young, glabrescent. Inflorescences compound corymbs, 30-80 flowered, 8-12 cm in diam., peduncles sparsely pubescent; pedicels 2-4 mm long, sparsely pubescent; flowers 6-8 mm in diam.; hypanthium abaxially pubescent; sepals triangular, ca. 1.5 mm long, glabrous or somewhat puberulous, apex acute, with reddish dentate glands along margin; petals creamy white, suborbicular, ca. 4 × 3 mm; stamens ca. 20; carpels 3(-4); styles 2 or 3, 2.5 mm. Infructescence sparsely pubescent or glabrous; pomes green when young, white or crimson when mature, globose or ovoid-globose, 5-8 mm in diam., sepals persistent erect; seeds brownish, reniform, 1.5-2.0 mm long; 2n = 34.

Phenology.

Flowering May-June; fruiting Sep-Oct.

Distribution and habitat.

Sorbus insignis is distributed in India, Nepal and China (Xizang) (Fig. 3 ). It is also mentioned as occurring in 'NW Yunnan’ China ( Lu and Spongberg 2003), but we have not yet seen any convincing specimens from Yunnan. All specimens labelled as ' S. insignis ' from Yunnan that we have examined were misidentified. It grows in broad-leaved forests on rocky slopes with an altitudinal range between 2500 and 3100 m.

Additional specimens examined.

China. Xizang province: Motuo, 2900 m alt., 25 Oct 2016, B. Xu et al. YLZB4493 (CDBI); Galung La, 2700 m, 18 Aug 1982, S.Z. Cheng & B.S. Li 0200 (PE).

India. Manipur state: Sirohifurar, 2500 m alt., Jan. 1982, G. Watt 5965 (P); Ching Sow, 2400-2700 m alt., 16 April 1982, G. Watt 6539 (P); Sikkim state: T. Thomson s.n. (E).

Nepal. Eastern Nepal: Sankhuwasabha, 29 Oct 1963, H. Hara et al. 6301809 (TI); Kuwa Pani, 2890 m alt., 23 Aug 1997, S. Noshiro et al. 9755184 (A, E); Kauma, 3130 m alt., 25 Sep 1991, Edinburgh Makalu Expedition 259 (E, KATH); Koping, 3040 m alt., 24 Oct 1991, Edinburgh Makalu Expedition 1019 (E); Jhakpu, 2750 m alt., 26 Sep 1971, P.R. Shikyo & M. Ohsawa 1069 (KATH); Bhyaha, 2880 m alt., 31 Oct 1981, P.R. Shakya 7296 (KATH); Taplejung, 2700 m alt., 30 Sep 1981, P.R. Shakya 6777 (KATH).

Figures

Figure 2. Type pictures of Sorbus insignis (Hook. f.) Hedl. (A barcode K 000758177) and S. harrowiana (Balf. f. & W. W. Smith) Rehd. (B barcode E 00072735).

Figure 3. Distribution of Sorbus insignis and S. harrowiana at county level.