Hedysarum qilianshanense P.L.Liu, sp. nov. (H. sect. Hedysarum)

Liu, Pei-Liang, Guo, Qian-Xi, Zhang, Jian-Qi, Xun, Lu-Lu, Lu, Yuan & Yue, Ming, 2024, Hedysarum qilianshanense sp. nov. (Fabaceae, Hedysareae), a new species from the Qilianshan Mountains in Gansu, China, PhytoKeys 237, pp. 103-116 : 103

Hedysarum qilianshanense P.L.Liu, sp. nov. (H. sect. Hedysarum)

Figs 3 , 4

Type.

China, Gansu Province, Su’nan County, the Heihe River valley, Xiaogushan , in crevice on stony slope, 2053 m above sea level (a. s. l.), 38°41′6.38″N, 110°3′9.98″E, 21 June 2019, P. L. Liu 458 (Holotype, WUK!, barcode WUK0536471; Isotypes, WUK!, barcodes WUK0536466-WUK0536470, WNU!) .

Diagnosis.

This new species is morphologically similar to H. przewalskii , but can be distinguished by its light purple to purple corolla (vs. light yellow to yellow corolla), 15-19 mm long standard (vs. 10-14 mm long standard), 14-16 mm long wings (vs. 10-14 mm long wings), 16-19 mm long keels (vs. 12-17 mm long keels), and glabrous ovaries and legumes (vs. often pubescent, sometimes glabrate or glabrous ovaries and legumes). The new species can be easily distinguished from H. neglectum by its bract shorter than pedicel (vs. bract longer than pedicel), and glabrous ovaries and legumes (vs. pubescent ovaries and legumes) (Table 2 ).

Description.

Perennial herbs, 30-100 cm tall. Main root stout, woody, up to 1.3 cm in diameter. Stems cespitose, ascending, branched; internodes glabrous or loosely pubescent, nodes pubescent. Leaves imparipinnate, alternate, 12-30 cm long; stipules connate, opposite to leaves, wide triangular, membranous, brown, glabrous, apex shallowly bilobed, lower ones 8-17 mm long, becoming smaller in upper part of stem; rachises sulcate, glabrous or sparsely pubescent; leaflets 9-19, opposite or alternate; petiolules ca. 1 mm long, pubescent; leaflet blades elliptic, ovate-elliptic, oblong, 12-40 × 7-25 mm, adaxial surface glabrous, abaxial surface sparsely pubescent along midvein, base wide cuneate or rounded, apex obtuse, rounded or retuse. Racemes axillary, exceeding leaves, 15-42 cm long, with 15-50 flowers, peduncles pubescent; pedicel 3-6 mm long, pubescent; bracts linear, with brown midvein, pubescent, 2-5 mm long; bracteoles 2, linear, with brown midvein, pubescent, 2-3.5 mm long; calyx tube campanulate, 3-4 mm long, pubescent; calyx teeth 5, pubescent, the two adaxial teeth triangular, ca. 1 mm long, the two lateral teeth narrowly triangular, 1.5-2.5 mm long, the abaxial tooth linear-triangular, 2-3 mm long; corolla light purple to purple; standard obovate, 15-19 × 5.5-7 mm, apex retuse, base attenuate; wings 14-16 × 2-2.5 mm, auricle linear, as long as claw, 2-3 mm long; keels 16-19 × 4-5 mm, auricle triangular, ca. 1 mm long; androecium diadelphous, 12-17 mm long; ovary linear, glabrous, style ca. 13 mm long. Legume a loment, divided into 2-4 articles, with a small beak at apex; articles elliptic, compressed, 8-10 mm × 6-7 mm, glabrous, with reticulate veins, with a narrow wing ca. 0.5 mm wide along the dorsal suture only. Seed reniform, yellow, ca. 3 × 2 mm.

Phenology.

Flowering and fruiting in June.

Distribution and habitat.

Hedysarum qilianshanense is only known from Su’nan, Gansu, China. It grows in stony slope and forest edge in valley, 2053-3000 m a. s. l.

Etymology.

The epithet Hedysarum qilianshanense is transliterated from the type location, Qilianshan Mountains in China. The Chinese vernacular name for this new species is 祁连山岩黄耆 ( qí lián shān yán huáng qí).

Other specimens examined (Paratypes).

China, Gansu Province, Su’nan County, Sidalong, Wulin’gou, on stony slope, 3000 m a. s. l., 21 June 1986, Sheng Huan Bao Dui 86055 (NWTC!); Su'nan County , Sidalong , Wulin’gou, in crevice on stony slope, 2542 m a. s. l., 38°28′1.67″N, 99°56′54.63″E, 21 June 2019, P. L. Liu 461 (WUK!, barcodes WUK0536462, WUK0536463, WNU!); Su'nan County , Sidalong, on slope on forest edge, 2632 m a. s. l., 38°27′26.6″N, 99°54′52.69″E, 21 June 2019, P. L. Liu 470 (WUK!, barcodes WUK0536464, WUK0536465, WNU!) .

Figures

Figure 3. Illustration of Hedysarum qilianshanense a root and basal part of stems b upper part of plant c calyx tube (split between an adaxial tooth and a lateral tooth) d bracteoles e standard f wing g keel h androecium i pistil j infructescence k legume. Drawn by Xiu-Zhen Wu.

Figure 4. Photos of Hedysarum qilianshanense from the field A habitat B plant C raceme D infructescence. Photographed by Pei-Liang Liu.