Astragalus australis
Fl. Franç. 2: 637. 1779.
Plants (10–)20–40(–50) cm, from superficial caudex, silky-strigose, villous, or villous-tomentose, hairs basifixed. Stems ascending, decumbent, or sprawling, silky-strigose, villous, or villous-tomentose. Leaves (1–)2–7(–10) cm; stipules clasping with margins touching but distinct or shortly connate at proximal nodes, distinct at distal nodes, (1–)2–7(–11) mm, often veined, semileathery; leaflet blades linear, lanceolate, oblong, elliptic, or elliptic-oblanceolate, 3–33(–35) mm, apex acute, subacute, or obtuse, surfaces glabrous, glabrate, or pubescent. Peduncles usually erect, rarely humistrate in fruit, (2–)2.5–15 cm, equal to or longer than subtending leaf, together with racemes usually shorter than stems. Racemes densely or loosely 6–40-flowered; axis 1.5–15 cm in fruit, elongating little after flowering; bracts 1.2–5 mm; bracteoles 0. Pedicels 0.8–2.2 mm 1.2–3.5 mm in fruit. Flowers 7–13.8(–14.5) mm; calyx 3.7–6.4 mm, villous or strigulose, tube 2.4–5 mm, lobes subulate, (1–)1.1–4 mm; corolla white to purplish or creamy white; wing apex bidentate; keel (6.1–)6.7–9.6 mm, shorter than wings. Legumes green, often with red or purple, becoming stramineous, ± straight or slightly curved abaxially, convex adaxially, not sulcate, obliquely ellipsoid, semi-ellipsoid, or narrowly oblong, laterally compressed, 10–30 × 3–9(–11) mm, papery, translucent, usually glabrous, sometimes strigose, hyaline septum 0–0.6 mm wide; stipe 2.5–8[–10] mm. Seeds 8–16.
Distribution
w North America, Eurasia.
Discussion
Varieties 5 (4 in the flora).
Astragalus australis is circumboreal and highly variable but with no intraspecific taxa recognized in a recent revision of Old World species (D. Podlech and S. Zarre 2013); Asiatic plants pass under several epithets (S. L. Welsh 2007). Differences among variants are in some instances part of a continuum; others are haphazard. The following key includes only the most conspicuous morphological variants and, even then, all specimens will not be included satisfactorily in one taxon or another.
Selected References
None.
Lower Taxa
Key
| 1 | Flowers (10.5–)11.5–13.8(–14.5) mm; calyces (4.7–)4.8–6.5 mm; wc, n Alaska, n Yukon. | Astragalus australis var. lepagei |
| 1 | Flowers 7.5–12.5 mm; calyces 4–8.4 mm; Yukon eastward to Quebec, southward to Nevada, New Mexico, and South Dakota. | > 2 |
| 2 | Leaves mostly petiolate, sometimes sessile distally; n, sw Yukon. | Astragalus australis var. muriei |
| 2 | Leaves sessile or subsessile; British Columbia eastward to Quebec, southward to Nevada and New Mexico. | > 3 |
| 3 | Legumes 3–7(–9) mm wide, usually not, or not much, bladdery-inflated; peduncles (2–)6.5–15 cm; British Columbia eastward to Quebec, southward to Nevada and New Mexico. | Astragalus australis var. glabriusculus |
| 3 | Legumes 7–9(–11) mm wide, bladdery-inflated; peduncles 3–6.5 cm; Olympic Mountains, Washington. | Astragalus australis var. olympicus |