Astragalus oyunicus D. Munkhtulga & S. Baasanmunkh, 2025

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

Fig. 4 View Figure 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 View 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 View Figure 6 )] GoogleMaps • Ulaanbaatar city, Bayanzurkh district, Gachuurt village , 47°55'52.3"N, 107°07'51.2"E, 1467 m, Yondon [Isotype UBU 0034202 !] GoogleMaps .

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 View Figure 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 ) GoogleMaps • 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 ) GoogleMaps .