Astragalus wuqiaensis Z. P. Yang, S. W. Zeng & P. Li sp. nov.

Diagnosis.

This species is characterized by erect stems forming dense clumps. The stems are densely covered with white stiff hairs at the base, becoming sparser upwards; the peduncles are nearly glabrous. Leaves are odd-pinnate, 4–8 cm long; leaflets 9–20 pairs, 2–8 mm × 2–5 mm, ovate to elliptic, glabrous adaxially, and with white short-appressed hairs abaxially. This set of characters readily distinguishes it from other species in sect. Cenantrum. Nevertheless, when examining herbarium specimens, it shows closer morphological affinity to Astragalus hoffmeisteri (Klotzsch) Ali (sect. Pseudosesbanella) and Astragalus zadaensis Podlech & L. R. Xu (sect. Galegiformes), both occurring in western Tibet. Detailed morphological differences among these three species are presented in Table 2.

Description.

Perennial herb, 50–100 cm tall. Stems erect, much-branched, hollow, ridged, densely covered with white stiff hairs at base, sparsely covered with white stiff hairs on upper parts, with both white and black stiff hairs intermixed at junction with petiole. Stipules ovate, 3–5 mm long, glabrous on both surfaces, margin with white stiff hairs. Leaves odd-pinnate, 4–8 cm long; petiole ca. 1 cm long, with short white appressed hairs, intermixed with black appressed hairs at base; leaflets 9–20 pairs, 2–8 mm × 2–5 mm, ovate to elliptic, apex emarginate with a short mucro, base suborbicular to cuneate, adaxial surface glabrous, abaxial surface with white short-appressed hairs, margin with white short-appressed hairs; petiolule ≤ 1 mm, with white short-appressed hairs. Inflorescence an axillary raceme, lax, with numerous nodding flowers; peduncles conspicuously exceeding leaves, with white appressed hairs; bracts lanceolate, 2–3 mm, strigose on both surfaces; pedicels 3–7 mm, strigose. Calyx tubular-campanulate, 6–7 mm × 3–4 mm, external surface with mixed white and black strigose hairs, teeth short, triangular, less than 1 mm long, calyx tube oblique at orifice. Corolla yellow; standard 17–20 mm long, blade suborbicular, apex emarginate, base attenuate into a 4–5 mm claw; wings slightly shorter than standard, blade oblong, ca. 7 mm long, base with a short auricle, claw ca. 10 mm long; keel shorter than wings, blade with a short auricle, ca. 6 mm long, claw ca. 10 mm long; stamens diadelphous (9 + 1); ovary 1 - locular, glabrous, slenderly long-stipitate, stigma without tufted hairs. Legumes 1 - locular, membranous, fusiform, slightly inflated, ca. 3–4 cm × ca. 1 cm, stipe extending beyond calyx tube, up to 1 cm long. Seeds reniform, 4–5 mm × 3–4 mm, testa brown, smooth, with black spots (Figs 2, 3).

Type.

China • Xinjiang: Wuqia County, Ulugqat Township, 40°02'12.7280"N, 74°35'06.3416"E, elev. 2757 m. 11 July 2024, fl & fr. Zhaoping YANG, Siwei ZENG et al. YZP 001513 (Holotype: PE 02648625!) (Fig. 3). China • Xinjiang: Wuqia County, Jigen Township, 40°14'37.39"N, 75°13'37.73"E, elev. 2857 m. 15 July 2021, fl & fr. Zhaoping YANG, Shiqiang SONG. YZP 000257 (Paratype: TARU 28021!).

Etymology.

The specific epithet wuqiaensis derives from the type locality of the new species.

Distribution and habitat.

This species is currently known only from Ulugqat Township and Jigen Township, Wuqia County, China (Fig. 4). In Ulugqat Township, it occurs on arid, rocky slopes at ca. 2,700 m elevation along watercourses, associated with perennial herbs (e. g., Orobanche amoena C. A. Mey., Artemisia spp., etc.) and other xerophytic vegetation. In Jigen Township, it grows in dry meadows at ca. 2,800 m.

Phenology.

Flowering from June to July; fruiting from July to August.

Vernacular name.

We propose a Chinese name, Wū qià Mò jiá Huáng qí (Chinese pronunciation), 乌恰膜荚黄芪 (Chinese name).

Conservation status.

Currently, A. wuqiaensis is known only from two isolated populations ca. 70 km apart. Wuqia County is located in a remote, mountainous border region with limited accessibility, resulting in incomplete floristic survey coverage. Moreover, the county adjoins Kyrgyzstan, and the two areas share a substantial number of plant species, making a potential transboundary distribution of this species plausible. Owing to the currently insufficient distribution data, an accurate assessment under IUCN criteria is not feasible. Therefore, we recommend that it be provisionally classified as Data Deficient (DD).