Sorbus gongshanensis Xin-Fen Gao & Meng Li, 2020

Li, Meng, Gao, Xin-Fen, Tian, Jing & Ju, Wen-Bin, 2020, Sorbus gongshanensis (Rosaceae), a new species from the Hengduan Mountains, China, PhytoKeys 144, pp. 1-9 : 1

Sorbus gongshanensis Xin-Fen Gao & Meng Li sp. nov. Figs 1 , 2

Type.

China. Yunnan: Gongshan County, Bingzhongluo Xiang. Vicinity of Fucai, on the north side of Nianwaluo River, ca. 10.8 direct km of Bingzhongluo, east side of Gaoligong Mountains, 28°0.47'N, 98°31.11'E, alt. 2780 m, 1 Sept. 2006. Gaoligong Shan Biodiversity Survey (2006) 31749 (holotype: GH; isotypes: CAS, KUN).

Diagnosis.

Similar to S. kurzii , but differs in its serrate leaflet margins toothed in the distal half or often almost to their base, reddish brown villous to glabrous hypanthium and reddish brown villous infructescences.

Description.

Shrubs or trees, 2-3 m tall. Bark gray. Branchlets tomentose when young, glabrous when old. Buds ovoid. Leaves pinnately compound, 8-10 × 5-5.5 cm; petiole 1.5-3 cm long; stipules membranous, caducous; rachis slightly winged, sulcate, sparsely tomentose; leaflets 2-4 pairs, opposite, elliptic, oblong to oblong-ovate, 2.8-3.5 × 1-1.5 cm, length/width ratio 2.4-3, surfaces essentially glabrous or sparsely (moderately) villous at flowering, usually glabrescent thereafter; blade paler abaxially, dull green adaxially; lateral veins 8-11 pairs, margins serrate, in the distal half or often almost to their base; base rounded or oblique, apex acute. Inflorescences corymbose, 4-5 × 2-3 cm, 3-15 flowered, sparsely reddish brown villous; stipules semi-orbicular, 0.5-0.8 × 1-1.3 cm, herbaceous, persistent in fruit; pedicels sparsely reddish brown villous. Flowers 6-8 mm in diam.; hypanthium reddish brown villous or glabrous, sepals 1-1.5(-2) mm long, margins entire; petals white, orbiculate to obovate, 3-4 mm long; stamens 15-20; carpels 1/2 adnate to hypanthium, styles 3-5. Infructescences sparsely reddish brown villous; pomes red, globose to subglobose, 6-8 mm in diam.; sepals inconspicuous, incurved when fruiting. Seeds brown, ovoid-lanceoloid, 3-4 × 1.2-1.5 mm, slightly asymmetric.

Etymology.

The specific epithet refers to the type locality, Gongshan County.

Phenology.

Flowering May-July, fruiting September-October.

Distribution and ecology.

Sorbus gongshanensis is known from the Yunnan & Xizang Province, China (Fig. 3 ). It grows in broad-leaved forests or on rocky slopes; 2500-3000 m.

Specimens examined.

China. Yunnan: Gongshan County, Cikai Xiang, east side of Gaoligong Mountains, along the Danzhu River, on the roadside from Nu Jiang to Danzhu, 27°37.82'N, 98°37.30'E, alt. 2650 m., 2 July 2000. Li Heng 11905 (GH, CAS, KUN). Xizang: Motuo County, 80k to Galung La, 29°42.30'N, 95°34.24'E, alt. 2782 m., 2 June 2015. Meng Li 00281 (CDBI, NF).

Conservation status.

The distribution of S. gongshanensis is based on three collections. The collection notes mention that S. gongshanensis is occasional in forests among boulders. There is no direct or indirect information about its current conservation status or possible threats. We therefore assign the conservation status of S. gongshanensis as 'Data Deficient (DD)' according to the IUCN red list criteria ( IUCN 2017).

Figures

Figure 1. Main morphological characters of Sorbus gongshanensis A flower, longitudinal section B fruiting branch C fruit, longitudinal section D fruit, cross section.

Figure 2. Sorbus gongshanensis A habit B stipules and reddish-brown hairs on infructescences C leaves D stomata of abaxial blade surface E inflorescence F perprolate shape pollen, length of polar axis (33.03 + / - 2.67 μm) and equatorial (16.61 + / - 2.44 μm) diameter G striate-perforate ornamentation of pollen grains.

Figure 3. Geographical distribution map of Sorbus gongshanensis from Yunnan and Xizang province, China.