Astragalus sect. Ammodendron in Flora of China @ efloras.org

54. Astragalus sect. Ammodendron Bunge, Mém. Acad. Imp. Sci. Saint Pétersbourg, sér. 7. 11(16): 128. 1868.

沙生组 sha sheng zu

Plants shrubby or subshrubby, with well-developed stems very densely covered with short, appressed, medifixed hairs. Stipules membranous, shortly adnate to petiole, high vaginate-connate behind stem, often up to top; leaflets in 1-3 pairs, rarely in more. Petals mostly lilac to violet, small. Legumes sessile, ± ovoid, ± keeled ventrally, mostly rounded to flat dorsally, 2-locular or rarely incompletely 2-locular; valves densely covered with long, soft, ± spreading, basifixed hairs and often also with short, appressed, ± medifixed hairs.

Seventy-three species: Afghanistan, China, Pakistan; N Africa (Egypt), C and SW Asia, E Europe; five species (one endemic) in China.

1 Leaflets in 1 or 2 pairs (2)

+ Leaflets in 2 or 3(or 4) pairs (3)

2 (1) Plants shrubby with hardening and persistent, subspiny rachises; calyx 6-7(-8) mm; standard 13-15 mm. 365 A. brachypus

+ Plants subshrubby; rachises not hardening and subspiny; calyx 4-5 mm; standard 8-9 mm. 368 A. iliensis

3 (1) Petiole stout, ca. 1.5 mm thick; leaflets in 3 pairs; standard with a claw longer than limb; legumes 10-12 mm, with subbasifixed, spreading hairs 2-3 mm, mostly sitting on small tubercles, without very short hairs. 369 A. macrostephanus

+ Petiole slender; leaflets in 2 or 3 pairs, basal leaves with only 1 pair; standard with a claw not longer than limb; legumes 5-8 mm, with both spreading hairs up to 1.5 mm and very short appressed hairs (4)

4 (3) Leaflets in 2 or 3(or 4) pairs, 4-15(-20) mm; raceme 4-10 cm, bracts ca. 2 mm; calyx 6-7 mm; standard at base gradually narrowed. 366 A. cognatus

+ Leaflets in 2 or 3 pairs, 15-30 mm; raceme 3-4 cm, bracts ca. 1 mm; calyx 5-5.5 mm; standard limb abruptly contracted into a rather long claw. 367 A. gebleri