OregonFlora: Astragalus succumbens vs. Astragalus collinus

	Astragalus succumbens	Astragalus collinus
	Columbia milkvetch, crouching milkvetch	hillside milkvetch
Habit	Plants perennial, caulescent, densely to thinly grayish hirsute, hairs basifixed.	Plants perennial, caulescent, villosulous or strigose throughout, hairs basifixed.
Stems	several, decumbent to erect, 2–40(50) cm.	several–numerous, decumbent to ascending or erect; in clumps, 15–50 cm.
Leaves	3–10(11) cm; leaflets (7)9–19, oblong to oblong-ovate, obovate to elliptic, 5–19 × 3–9 mm; tips acute to obtuse or retuse; surfaces abaxially hirsute, adaxially hirsute to glabrescent; stipules (1.5)2.5–8(9) mm; free.	3–9(10.5) cm; leaflets (9)11–21(25), oblong-oblanceolate to linear-elliptic, 4–20(22) × 2–6 mm; tips truncate-retuse to obtuse; surfaces abaxially pubescent, adaxially pubescent, glabrescent, or glabrous; stipules 2–5(7) mm; free.
Inflorescences	racemes densely 10–25-flowered; peduncles 1.5–5.5 cm; bracts (2.5)4–12 mm; pedicels 0.5–2.3 mm; bracteoles 0–2.	racemes closely (10)15–40(55)-flowered; peduncles (4)5–16 cm; bracts 1.5–3.5 mm; pedicels 0.8–2.8 mm; bracteoles 2, rarely 0.
Flowers	spreading-ascending at anthesis; calyces 9.5–13(15) mm; hirsute to hirsutulous with all white or white with some black hairs; tubes 7–8.6 mm; teeth subulate to linear-lanceolate, 2.5–5.5 mm; corollas 14–20(23) mm, bicolored; banners pink to white; wings white; keels pink to purple; tips spotted; ovules 27–38.	nodding at anthesis; calyces gibbous-saccate at bases, 7–12.3 mm, villosulous with white or some black hairs; tubes 5.8–9.4 mm; teeth lanceolate to triangular, 0.8–2.7(3.5) mm; corollas (10.5)12–17.2 mm, white, cream, ochroleucous to lemon yellow; ovules 7–18.
Fruits	bilocular, ascending, lunately linear-lanceolate or -oblong, arcuate to straight, triquetrous, strongly compressed, deeply sulcate dorsally; (20)25–40 × 4–8 mm, glabrous; valves cartilaginous; stipes 0.	unilocular, pendulous, linear- or lance-oblong to lunate-oblong; straight or gently incurved, laterally compressed, bicarinate, 7–25 × 2.3–4.5 mm, villosulous or strigillose to glabrate; valves coriaceous; stipes (3.5)5–15 mm;
2n	=24.	=24.

	Astragalus succumbens	Astragalus collinus
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Sandy hills and dunes, roadbanks, sagebrush. Flowering Apr–Jul. 50–900 m. Col. WA. Native.	2 varieties.
Source	Flora of Oregon, volume 2, page 674 Richard Halse	Flora of Oregon, volume 2, page 661 Richard Halse
Sibling taxa	A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, A. beckwithii, A. californicus, A. calycosus, A. canadensis, A. caricinus, A. collinus, A. conjunctus, A. curvicarpus, A. cusickii, A. diaphanus, A. drummondii, A. eremiticus, A. filipes, A. gambellianus, A. geyeri, A. hoodianus, A. howellii, A. inflexus, A. iodanthus, A. kentrophyta, A. lemmonii, A. lentiginosus, A. malacus, A. misellus, A. mulfordiae, A. multiflorus, A. newberryi, A. nudisiliquus, A. obscurus, A. peckii, A. platytropis, A. purshii, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. tegetarioides, A. tetrapterus, A. toanus, A. tweedyi, A. tyghensis, A. umbraticus, A. vallaris, A. whitneyi	A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, A. beckwithii, A. californicus, A. calycosus, A. canadensis, A. caricinus, A. conjunctus, A. curvicarpus, A. cusickii, A. diaphanus, A. drummondii, A. eremiticus, A. filipes, A. gambellianus, A. geyeri, A. hoodianus, A. howellii, A. inflexus, A. iodanthus, A. kentrophyta, A. lemmonii, A. lentiginosus, A. malacus, A. misellus, A. mulfordiae, A. multiflorus, A. newberryi, A. nudisiliquus, A. obscurus, A. peckii, A. platytropis, A. purshii, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. succumbens, A. tegetarioides, A. tetrapterus, A. toanus, A. tweedyi, A. tyghensis, A. umbraticus, A. vallaris, A. whitneyi
Subordinate taxa		A. collinus var. collinus, A. collinus var. laurentii
Web links	Local floras: OR, WA Local Web sites: Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Astragalus succumbens

Astragalus collinus

Columbia milkvetch, crouching milkvetch

hillside milkvetch

Habit

Plants perennial, caulescent, densely to thinly grayish hirsute, hairs basifixed.

Plants perennial, caulescent, villosulous or strigose throughout, hairs basifixed.

Stems

several, decumbent to erect, 2–40(50) cm.

several–numerous, decumbent to ascending or erect; in clumps, 15–50 cm.

Leaves

3–10(11) cm;

leaflets (7)9–19, oblong to oblong-ovate, obovate to elliptic, 5–19 × 3–9 mm;

tips acute to obtuse or retuse;

surfaces abaxially hirsute, adaxially hirsute to glabrescent;

stipules (1.5)2.5–8(9) mm; free.

3–9(10.5) cm;

leaflets (9)11–21(25), oblong-oblanceolate to linear-elliptic, 4–20(22) × 2–6 mm;

tips truncate-retuse to obtuse;

surfaces abaxially pubescent, adaxially pubescent, glabrescent, or glabrous;

stipules 2–5(7) mm; free.

Inflorescences

racemes densely 10–25-flowered;

peduncles 1.5–5.5 cm;

bracts (2.5)4–12 mm;

pedicels 0.5–2.3 mm;

bracteoles 0–2.

racemes closely (10)15–40(55)-flowered;

peduncles (4)5–16 cm;

bracts 1.5–3.5 mm;

pedicels 0.8–2.8 mm;

bracteoles 2, rarely 0.

Flowers

spreading-ascending at anthesis;

calyces 9.5–13(15) mm; hirsute to hirsutulous with all white or white with some black hairs;

tubes 7–8.6 mm;

teeth subulate to linear-lanceolate, 2.5–5.5 mm;

corollas 14–20(23) mm, bicolored;

banners pink to white;

wings white;

keels pink to purple;

tips spotted;

ovules 27–38.

nodding at anthesis;

calyces gibbous-saccate at bases, 7–12.3 mm, villosulous with white or some black hairs;

tubes 5.8–9.4 mm;

teeth lanceolate to triangular, 0.8–2.7(3.5) mm;

corollas (10.5)12–17.2 mm, white, cream, ochroleucous to lemon yellow;

ovules 7–18.

Fruits

bilocular, ascending, lunately linear-lanceolate or -oblong, arcuate to straight, triquetrous, strongly compressed, deeply sulcate dorsally; (20)25–40 × 4–8 mm, glabrous;

valves cartilaginous;

stipes 0.

unilocular, pendulous, linear- or lance-oblong to lunate-oblong; straight or gently incurved, laterally compressed, bicarinate, 7–25 × 2.3–4.5 mm, villosulous or strigillose to glabrate;

valves coriaceous;

stipes (3.5)5–15 mm;

=24.