Astragalus teshigicus D. Munkhtulga & S. Baasanmunkh, 2025

Munkhtulga, Dariganga, Baasanmunkh, Shukherdorj, Nyamgerel, Nudkhuu, Park, Jong Ho, Tsegmed, Zagarjav, Tojibaev, Komiljon Sh. & Choi, Hyeok Jae, 2025, Morphological and phylogenetic analysis approach to three new species and a new section of Astragalus (Fabaceae) from Mongolia, PhytoKeys 255, pp. 51-73 : 51-73

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

Fig. 5

Type.

Mongolia. Bulgan province, Teshig soum, Baga Baysgalan , 49.9679, 102.5867, 1128 m, 05 June 2018, B. Oyuntsetseg & Sh. Baasanmunkh NW 11 [Holotype UBU 0002138 ! (Fig. 6 B ), Isotype UBU 0002139 !] .

Diagnosis.

The morphological features of A. teshigicus are similar to that of A. laguroides but differ by its raceme oblong or oblong-cylindrical (vs. ovoid), calyx rather densely covered with spreading, straight only white hairs 2 mm (vs. densely covered with asymmetrically bifurcate to basifixed, tangled, spreading white hairs 1–2 mm, at outer side of the teeth and sometimes at the nerves of the tube also with black hairs), leaves 8–18 cm (vs. 3–14 cm long), leaflets in 4–6 pairs, elliptical, 14–20 × 5–8 mm (vs. 3–5 pairs, narrowly elliptic, 8–25 × 3–6 mm) (Table 2 ).

Description.

Plants perennial, 8-20 cm tall, acaulescent. Stems up to 1 cm, densely appressed white hairy. Stipules 4-5 mm long, broadly triangular-acuminate, densely covered with spreading or ascending hairs. Leaves 8-18 cm; petiole 3-7 cm, like the rachis covered with appressed white hairs. Leaflets in 4-6 pairs, elliptical, 14-20 × 5-8 mm, on both sides densely covered with medifixed, subappressed hairs, acute to rarely obtuse. Peduncles 6-12 cm, with medifixed, appressed hairs. Racemes oblong or oblong-cylindrical (3.5) 4-7 (8) cm long, rather densely many-flowered. Bracts scarious, 5.5-6 mm, narrowly triangular, sparsely covered with ascending only white hairs, at the margins covered with spreading white hairs up to 1.5-2 mm. Calyx 12-15 mm, at the beginning of anthesis tubular, soon ovoid-inflated, densely covered with basifixed, ± spreading, rigid white hairs 1.5-2 mm; teeth subulate, 2-3 mm. Petals purplish. Standard 20-24 mm; blade 4.5-5.5 mm wide, obovate, slightly constricted in the middle, slightly emarginate, at the base gradually narrowed. Wings 17-22 mm; blades oblong, rounded, 5-5.5 × 2-3 mm; auricle c. 1 mm; claw 8-9 mm. Keel 14-18 mm; blades 4-4.5 × 2-3 mm; claw c. 8 mm. Ovary sessile. Legumes enclosed in the calyx, oblong, 4-5.5 × 2-2.5 mm, with a hooked beak c. 1 mm, unilocular; densely covered with spreading white hairs.

Distribution.

Endemic to Mongolia. This species is found only in a single location in the northern part of the country (Fig. 9 ).

Habitat.

This species grows in steppe areas including mountain slopes, rocky and stony mountains.

Etymology.

The species epithet refers to the location where the species was collected.

Figures

Figure 5. Astragalus teshigicus in Mongolia A general habit B raceme C bract D calyx E standard F keel G wings H pistil I stamens J leave K omission of medifixed hairs on the upper side of the leaf L stipules, inside view M stipules, outside view N pod. (Photo credits: D. Munkhtulga and B. Oyuntsetseg).

Figure 6. Type specimens of Astragalus species A A. uvsicus (UBU 0039100) B A. teshigicus (UBU 0002138) C A. oyunicus (UBU 0039102) D A. laguroides (BM 000632540) E A. tamiricus (LE 01017820) F A. gobi-altaicus (LE 01016096).

Figure 9. Distribution map of the studied Astragalus species from the sections Laguropsis and Uvsicus in Mongolia.