OregonFlora: Astragalus purshii vs. Astragalus purshii var. purshii

	Astragalus purshii	Astragalus purshii var. purshii
	Pursh's milkvetch, woollypod milkvetch	Pursh's milkvetch
Habit	Plants perennial, acaulescent to shortly caulescent, densely villous to villous-tomentose, hairs basifixed.
Stems	prostrate, loosely to densely tufted, 0–20 cm.	0–10 cm.
Leaves	1–12(17) cm; leaflets (3)5–17(21), elliptic to oblanceolate, 2–14(20) × 1–7 mm; tips obtuse to acute; surfaces densely villous; stipules 2.5–15 mm; free.	(1.5)3–10(15) cm; leaflets (5)7–15(17).
Racemes		1–6-flowered.
Inflorescences	racemes or subumbels, 1–12-flowered; peduncles 1–14 cm; bracts 4–9 mm; pedicels 2–4.3 mm; bracteoles 0–2.
Flowers	ascending at anthesis; calyces 5.5–16(19) mm, often purple, villous-pilose with white or mixed white and black hairs; tubes 8.5–12.5 mm; teeth subulate, 2.2–6 mm; corollas 19–27 mm; whitish to ochroleucous or pink-purple; ovules 14–40(46).	calyces (12)13–16(19) mm; corollas 19–25(27) mm, white or cream; keel tips spotted; wings and banners dull bluish purple-tipped.
Fruits	unilocular, ascending, obliquely ovoid, usually curved, obcompressed, scarcely to deeply sulcate; (7)13–27(30) × 3.5–11 mm, densely white to tawny tomentose or densely villous; hairs nearly always concealing valve surfaces; valves coriaceous, sessile or on gynophores 0–1.6 mm.	not or very shallowly sulcate ventrally.
2n		=22.

	Astragalus purshii	Astragalus purshii var. purshii
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Western North America. ~8 varieties; 4 varieties treated in Flora. Throughout western North America, particularly in the Intermountain Region, this is a low, tufted milkvetch with white or gray villous hairs and pods resembling balls of cotton. Barneby (1964) stated, “Attempts to devise a practical key to the varieties of A. purshii are never wholly successful.” Variety ophiogenes, the Snake River milkvetch, a native of Idaho, has been reported from Malheur County, but this is apparently based on misidentifications of A. purshii var. lagopinus. Variety ophiogenes has 3–11-flowered racemes and 9–17 leaflets.	Dry hillsides and plains; sagebrush communities. Flowering May–Jun. 400–2200 m. BR, BW, Col, ECas, Owy. CA, ID, NV, WA; north to British Columbia, northeast to Saskatchewan, east to ND, southeast to UT, CO. Native.
Source	Flora of Oregon, volume 2, page 671 Richard Halse	Flora of Oregon, volume 2 draft 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. 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	A. purshii var. glareosus, A. purshii var. lagopinus, A. purshii var. tinctus
Subordinate taxa	A. purshii var. glareosus, A. purshii var. lagopinus, A. purshii var. purshii, A. purshii var. tinctus
Synonyms	Astragalus purshii var. ophiogenes
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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 purshii var. purshii

Pursh's milkvetch, woollypod milkvetch

Pursh's milkvetch

Habit

Plants perennial, acaulescent to shortly caulescent, densely villous to villous-tomentose, hairs basifixed.

Stems

prostrate, loosely to densely tufted, 0–20 cm.

0–10 cm.

Leaves

1–12(17) cm;

leaflets (3)5–17(21), elliptic to oblanceolate, 2–14(20) × 1–7 mm;

tips obtuse to acute;

surfaces densely villous;

stipules 2.5–15 mm; free.

(1.5)3–10(15) cm;

leaflets (5)7–15(17).

Racemes

1–6-flowered.

Inflorescences

racemes or subumbels, 1–12-flowered;

peduncles 1–14 cm;

bracts 4–9 mm;

pedicels 2–4.3 mm;

bracteoles 0–2.

Flowers

ascending at anthesis;

calyces 5.5–16(19) mm, often purple, villous-pilose with white or mixed white and black hairs;

tubes 8.5–12.5 mm;

teeth subulate, 2.2–6 mm;

corollas 19–27 mm; whitish to ochroleucous or pink-purple;

ovules 14–40(46).

calyces (12)13–16(19) mm;

corollas 19–25(27) mm, white or cream;

keel tips spotted;

wings and banners dull bluish purple-tipped.

Fruits

unilocular, ascending, obliquely ovoid, usually curved, obcompressed, scarcely to deeply sulcate; (7)13–27(30) × 3.5–11 mm, densely white to tawny tomentose or densely villous;

hairs nearly always concealing valve surfaces;

valves coriaceous, sessile or on gynophores 0–1.6 mm.

not or very shallowly sulcate ventrally.

=22.

Astragalus purshii var. purshii

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Western North America. ~8 varieties; 4 varieties treated in Flora.

Throughout western North America, particularly in the Intermountain Region, this is a low, tufted milkvetch with white or gray villous hairs and pods resembling balls of cotton. Barneby (1964) stated, “Attempts to devise a practical key to the varieties of A. purshii are never wholly successful.” Variety ophiogenes, the Snake River milkvetch, a native of Idaho, has been reported from Malheur County, but this is apparently based on misidentifications of A. purshii var. lagopinus. Variety ophiogenes has 3–11-flowered racemes and 9–17 leaflets.

Dry hillsides and plains; sagebrush communities. Flowering May–Jun. 400–2200 m. BR, BW, Col, ECas, Owy. CA, ID, NV, WA; north to British Columbia, northeast to Saskatchewan, east to ND, southeast to UT, CO. Native.

Source

Flora of Oregon, volume 2, page 671
Richard Halse

Flora of Oregon, volume 2 draft
Richard Halse

Sibling taxa