Astragalus oyunicus D. Munkhtulga & S. Baasanmunkh sp. nov.

Fig. 4

Diagnosis.

The new species is close to A. gobi-altaicus, but differs by its leaves having leaflet narrowly elliptic, 15–18 × 4–7 mm, apex acute (vs. oblanceolate or narrowly elliptic to elliptic, 7–18 × 5–10 mm, apex mucronate) and raceme oblong to oblong-cylindrical, 3–8 cm long (vs. ovoid to oblong, 3–4 cm long). It is also similar to A. laguroides in leaf shape and general habit, but differs in its stipules broadly triangular-acuminate, 4–6 mm long (vs. narrowly triangular-acuminate, 5–8 (– 10) mm long) and pod densely covered with spreading white and fewer black hairs 2 mm (vs. covered with subappressed to spreading white hairs 1–1.5 mm, smaller black hairs amount greater than the apex) (Table 2).

Type.

Mongolia. Khentii province, Bayankhutag soum, 46°54'10.2"N, 110°12'51.9"E, 1166 m, 05 August 2023, B. Oyuntsetseg & D. Munkhtulga Khen- 2023 [Holotype UBU 0039102! (Fig. 6 C)] • Ulaanbaatar city, Bayanzurkh district, Gachuurt village, 47°55'52.3"N, 107°07'51.2"E, 1467 m, Yondon [Isotype UBU 0034202!] .

Description.

Plants perennial, 5-15 cm tall, acaulescens, in vegetative parts covered with ± medifixed, appressed white hairs c. 1 mm. Rootstock divided with short to elongated blackish brown branches. Stipules broadly triangular-acuminate, 4-6 mm, shortly adnate to the petiole, otherwise free from each other, densely covered with hairs up to 1.5 mm, at the margins also with basifixed hairs. Leaves 5-12 (- 15) cm; petiole 2-4 cm, like the rachis covered with medifixed, appressed hairs. Leaflets in 3-5 pairs, narrowly elliptic, 15-18 × 4-7 mm, on both sides densely hairy, apex acute. Peduncles 3-7 cm, rather densely to densely covered with symmetrically to asymmetrically bifurcate, flexuose, subappressed white hairs. Racemes ovoid to oblong 3-4 cm long. Bracts whitish, 5-6 mm, narrowly triangular, with strongly asymmetrically bifurcate, ± spreading white hairs. Calyx at beginning of anthesis tubular, later on ovoid-inflated, 10-12 mm long, covered with basifixed, spreading, straight white and fewer black hairs 1-2 mm; teeth subulate, 2-3 mm. Petals violet. Standard 18-20 mm; blade 5-6 mm wide, obovate, slightly constricted in the middle, emarginate, at the base gradually narrowed. Wings 14-16 mm; blades narrowly oblong, obtuse, 5.5-6.5 × 2-2.5 mm; auricle c. 1.5 mm; claw c. 9 mm. Keel 12-14 mm; blades 4-4.5 × 3 mm; claw 8-8.5 mm. Ovary sessile. Legumes enclosed in the calyx, 6-7 × 3-4 mm, with a hooked beak c. 1 mm, unilocular; densely covered with spreading white and fewer black hairs c. 2 mm.

Distribution.

Endemic to Mongolia (Fig. 9).

Habitat.

This species grows in stony mountain slopes and low isolated rounded hills of the steppe region.

Etymology.

The species is named after Prof. Batlai Oyuntsetseg who is a botanist in Mongolia.

Additional specimens examined.

Mongolia. Mongolian Dauria region: • Ulaanbaatar city, Chingeltei district, Zuun salaa, 23 August 1963 (UBU 0032447) • Ulaanbaatar city, Narangiin enger, 25 July 1967, L. Purevsuren (UBU 0026331, UBU 0026338) • Ulaanbaatar city, Songinokhairkhan district, Tolgoit, Narangiin enger, 10 August 1967, Tsogoo (UBU 0026224, UBU 0032448, UBU 0032449, UBU 0039988 - UBU 0039990) • Khentii province, Jargalant Khan soum, Kherlen river, 07 July 1979, V. I. Grubov & A. Mundaashev 321 (UBA) • Ulaanbaatar city, Chingeltei district, Shadivlan, 48°01'00"N, 106°54'01"E, 1520 m, 06 June 2021, B. Oyuntsetseg & A. Anudari (UBU 0014416) • Middle Khalkh region: Tuv province, Buren soum, Ikher-Ukhaa, 22 July 1976, Tumurtogoo (UBU 0039987) • Govisumber province, Sumber soum, 23 July 1992, B. Oyuntsetseg & Oyunchimeg (UBU 0031855) • Khentii province, Tsenkhermandal soum, Batkhairkhan mountain, 47°42'30"N, 109°05'34.8"E, 1459 m, 28 May 2020, D. Munkhtulga (UBU 0031854) .