Sorbus doshonglaensis Xin Chen, Xiao C. Zhang & Chen Q. Tang, 2021

Tang, Chen-Qian, Zhang, Xiao-Chen & Chen, Xin, 2021, Sorbus doshonglaensis (Rosaceae), a new species from southeastern Xizang, China, Phytotaxa 489 (1), pp. 99-103 : 99-102

Sorbus doshonglaensis Xin Chen, Xiao C. Zhang & Chen Q. Tang , sp. nov. ( Figs. 1 , 2 )

Type: — CHINA. Xizang: Nyingchi City, Mainling County, Paizhen Town , Doshong La Snow Mountain , 29°29′29.08″N, 94°55′50.44″E, elev. 3835 m, 15 September 2017, X. Chen, X. C . Zhang , Z . R . Xiong 1079 (holotype NF-2008688!, isotypes NF-2008685!, IBSC!)

Diagnosis:—The new species is similar to S. kiukiangensis T. T. Yü (1963: 225) , but differs in having (4–)5–7 pairs (not 7–9 pairs) of leaflets, ovate to semi-orbicular (not lanceolate) stipule, and yellowish white (not red or reddish brown) fruits.

Shrubs up to 2.5 m tall. Branchlets grayish brown to blackish brown, glabrous, young shoots reddish brown, with sparse, ellipsoid yelllowish white lenticels. Buds ovoid, apex acute; scales several, reddish brown, densely brown villous along margin. Leaves imparipinnate, 8–13.6 cm long; petiole 1–2.4 cm long; stipules caducous, ovate to semiorbicular, 5.1–9.8 mm long, 2.5–6.5 mm wide, unequally 2-lobed, margin serrate apically, sparsely brown tomentose; rachis shallowly sulcate adaxially, distinctly narrowly winged, yellowish brown tomentose; leaflets (4–)5–7 pairs, unequal in size, the terminal and basal ones slightly smaller than middle ones, 8–13.8 mm apart, middle ones 2.8–5 cm long, 1.1–2.5 cm wide, elliptic-oblong to oblong, base oblique, cuneate on one side, sub-rounded on another side, apex usually obtuse, rarely acute, margin serrate from nearly 1/2–2/3 above base, with 4–8(–12) teeth per side, abaxially brown tomentose, densely along mid-vein, adaxially white villous, midrib distinctly impressed adaxially and raised abaxially, secondary veins 8–11 pairs, slightly impressed adaxially and raised abaxially. Infructescence a compound corymb, terminal or in axillary of the uppermost 1–2 leaves, densely 17–33-fruited; peduncle 2.8–6 cm long, 1.1–2.4 mm in diameter, pedicels 1.4–2.3 cm long, 0.8–1.4 mm in diameter, both densely brown tomentose; bract ovate to semi-orbicular, 7.5–7.9 mm long, 2–3.8 mm wide, 2-lobed, few teethed. Flowers unseen. Fruits yellowish white, yellowish green when young, subglobose, 6.1–8.2 mm long, 6.3–9.1 mm in diameter, 4–5-loculed, sparsely pinkish lenticellate, with persistent flower parts apically; persistent sepals red, erect, triangular-ovate, apex acute, 2.4–2.6 cm long, 1.8–2.4 cm wide, apex brown tomentose adaxially and white glands abaxially; persistent stamens 1.9–2.4 mm long; persistent styles 4 or 5, 2– 2.5 mm long, free, brown villous basally. Seeds ellipsoid, apex obtuse, base beak-like, dark brown, 2.7–4 mm long, 1.8–2.6 mm in diameter, 1–1.9 mm thick.

Phenology:— Sorbus doshonglaensis was observed in fruiting in September.

Distribution and ecology:— Sorbus doshonglaensis is known only from type locality, Doshong La Snow Mountain, Mainling County, southeastern Xizang. It grows in alpine shrub meadows, at elevations of 3430–3840 m. The associates are mainly species of Rhododendron Linnaeus (1753: 392) including R. anthopogon D. Don , R. calostrotum I. B. Balfour & Kingdon Ward, R. 1audandum Cowan, etc.

IUCN Red List category:—Only one population is known from the type locality and comprised about 10 plants. Adequate data on its distribution and population status need to be further collected. At present, we assign the conservation status of S. doshonglaensis as “Data Deficient (DD)” according to IUCN Red List Categories and Criteria (IUCN 2017).

Etymology:—The specific epithet “ doshonglaensis ” refers to the type locality, Doshong La Snow Mountain in southeastern Tibet.

Vernacular name: ‘ ƗǾǛAE楸 (duo xiong la hua qiu)’ in Chinese.

Specimens examined:— CHINA. Xizang: Nyingchi City, Mainling County, Paizhen Town , Doshong La Snow Mountain , 29°29′31.05″N, 94°55′44.98″E, elev. 3794 m, 15 September 2017, X. Chen, X. C . Zhang , Z . R . Xiong 1050 ( NF); same locality, 29°29′30.95″N, 94°55′46.13″E, elev. 3796 m, 15 September 2017, X. Chen, X. C . Zhang , Z . R . Xiong 1052 ( NF); same locality, 29°29′30.07″N, 94°55′47.57″E, elev. 3432 m, 15 September 2017, X. Chen, X. C . Zhang , Z . R . Xiong 1084 ( NF) .

Figures

FIGURE 1. Sorbus doshonglaensis sp. nov.—A. habit (Doshong La Snow Mountain, Nyingchi City, Xizang).—B. sterile branch showing abaxial side of leaves and the stipules.—C. fruits.—D. fertile branch and leaves.

FIGURE 2. Sorbus doshonglaensis sp. nov.—A. fruiting branch and leaves.—B. stamens and adaxial side of the sepal;—C. styles.—D. fruit with the persistent flower parts.—E. seed. (Drawn by Yuxuan Bao. scale bar A = 2 cm, D = 5 mm, B, C, E = 2 mm).