Astragalus L.
Milk vetch.
Plants with single unbranched stems (rarely), or with leaves or spreading stems arising from a caudex (usually); 2–30 cm high. Aerial stems erect, or decumbent; glabrous, or sparsely hairy, or densely hairy. Leaves distributed along the stems; alternate, or opposite (compact plants of Astragalus alpinus have leaves that may appear opposite). Stipules leaf-like, or scale-like; sheathing, or not sheathing; brown, or green. Petioles 5–35 mm long. Blades 1.5–5.5 cm long; 8–25 mm wide; with pinnate veins; glabrous, or hairy; with hairs on the adaxial surface only, or with hairs on the abaxial surface only, or with hairs equally dense on both surfaces. Leaflet arrangement pinnate; leaflets 7–23; leaflets 3–12 mm long; leaflets linear, or oblong, or elliptic, or lanceolate.
Flowering stems 1.5–10 cm long; without leaves; hairy. Inflorescence racemose; 0.5–9 cm long. Flowers per inflorescence 3–16; medium-sized, 5–15 mm in diameter or length. Calyx brown, or black; tubular, or funnel-form; 5-lobed. Petals 5; green, or white, or purple, or blue; 6–15 mm long. Corolla papilionaceous. Corolla keel blunt. Stamens 10. Stipes 0–8 mm long (in fruit). Stigmas per style 1. Ovules 3–12. Fruit with calyx persisting; a legume; spherical (almost), or ellipsoid, or ovoid; 5–26 mm long; 2.5–6 mm wide; stalked; dehiscent; black, or brown; glabrous, or hairy. Legume nearly 2-locular by intrusion of placenta. Seeds 3–12; 1–2 mm long; brown.
Chromosome information. 2n = 16, 32, 48.
Distribution. Circumpolar, or amphi-Beringian, or North American. Arctic Islands: Baffin, Parry Islands, Banks, Victoria, Somerset, King William, Southampton, Coats.
Notes. The name Astragalus is from the Greek for ankle-bone, used in ancient times as a form of dice. It has been supposed that word was applied to the plant, because of the rattle of seeds within the dry pods of some species.
Cite this publication as: J.M. Gillett, L.L. Consaul, S.G. Aiken and M.J. Dallwitz (1999 onwards). ‘Fabaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.’ Version: 15th November 2000. http://http://www.mun.ca/biology/delta/arcticf/. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).