Astragalus species

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Scientific Name Astragalus agrestis USDA PLANTS Symbol ASAG2
Common Name Field Milkvetch, Purple Milkvetch ITIS Taxonomic Serial No. 25405
Family Fabaceae (Pea) Burke Museum of Natural History Ref. Click Here
Description Life zones and habitat: High Plains to montane (5000 to 10500 ft.); moist meadows, forests, along streams.
Plant: Perennial with numerous slender creeping to erect stems, 5 to 12 inches long.
Leaves: Alternate compound leaves, 2 to 4 inches long, each with 11 to 19 elliptic to oblong leaflets 3/8 to 3/4-inch long.
Inflorescence: Dense, oval-shaped racemes on short peduncles, up to 1 inch across and long; 5 to 15 erect pea-like flowers, each 1/2 to 3/4-inch long with pink-purple to blueish and white petals; calyx tube with grey or black hairs.
Bloom Period: May to July.
References: www.montanaplantlife.org and "Flora of Colorado" by Jennifer Ackerfield.
BONAP Distribution Map Colorado Status:
Native
Scientific Name Astragalus alpinus var. alpinus USDA PLANTS Symbol ASALA4
Common Name Alpine Milkvetch ITIS Taxonomic Serial No. 192322
Family Fabaceae (Pea) SEINet
Reference
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Description Life zones and habitat: Montane to alpine (7500 to 12700 ft.); often in moist areas (woodlands, meadows, around streams and lakes), aspen groves and on tundra, cold, dry, exposed areas.
Plant: Mat-forming perennial with weak, slender, hairy stems, very short or up to 10 inches long.
Leaves: Pinnately-compound basal leaves 2 to 8 inches long; 15-25 leaflets, less than 1/4 to 3/4-inch long, oval-ovate to nearly round, slightly hairy surfaces.
Inflorescence: Small racemes on peduncles 3/4 to 1-1/2 inches long, with 7 to 17 nodding pea-like flowers with white to purplish petals; each blossom less than 1/2-inch long; calyx tube with small black hairs.
Bloom Period: June to August.
References: "Guide to Colorado Wildflowers" by G.K. Guennel, "Flora of Colorado" by Jennifer Ackerfield and SEINet.
BONAP Distribution Map Colorado Status:
Native
Scientific Name Astragalus flexuosus USDA PLANTS Symbol ASFL2
Common Name Flexible Milkvetch ITIS Taxonomic Serial No. 25517
Family Fabaceae (Pea) SEINet
Reference
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Description Life zones and habitat: Plains to montane (5500 to 10300 ft.); drier soils in meadows, and other open areas.
Plant: Sprawling perennial less than 2 ft. tall with a tangled, vine-like appearance; several to many stems tending to recline with up-turned tips; herbage moderately hairy (finely strigose).
Leaves: Odd-pinnately-compound leaves 2 to 3 inches long with each blade divided into 11 to 25 linear to oblong-lanceolate leaflets, 1/8 to 3/4-inch long; tips bluntly-rounded or with a small notch.
Inflorescence: Loose racemes arising from the leaf axils on peduncles 1 to 2-3/8 inches long with 10 to 30 pea-like blossoms; corollas are whitish to pale purple, 3/8 to 5/8 inch long on a very short stalk; the calyx tube has fine hairs and is less than 1/4-inch long with pointed lobes
Bloom Period: May to August.
References: "Flora of Colorado" by Jennifer Ackerfield, Minesota Wildflowers and Minnesota Dept. of Natural Resources.
BONAP Distribution Map

Colorado Status:
Native
Scientific Name Astragalus gracilis USDA PLANTS Symbol ASGR3
Common Name Slender Milkvetch ITIS Taxonomic Serial No. 25528
Family Fabaceae (Pea) SEINet
Reference
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Description Life zones and habitat: Plains and foothills (3500 to 6500 ft.); often calcareous soils on open prairies, wooded or brushy hillsides, ravines, and roadsides.
Plant: Erect, ascending, or decumbent, 1 or more branched weak stems 6 to 16 inches long; stems covered with fine, short, appressed hairs.
Leaves: Odd-pinnately-compound leaves 3/4 to 2-3/4 inches long with each blade divided into 9 to 17 narrowly-linear or linear-oblong widely separated leaflets, 1/4 to 3/4-inch long, less than 1/10 inch wide up to 3/8-inch long; upward-curled edges.
Inflorescence: Loose spike-like racemes 2 to 8 inches long with 3 to 50 pea-like blossoms; corollas dark purple to pale pinkish or sometimes whitish with purple keel tips, fading to yellowish; banner often purple-veined.
Bloom Period: May to July.
References: "Flora of Colorado" by Jennifer Ackerfield, "Manual of the Vascular Plants of Texas" by Correll and Johnston and Kansas Wildflowers and Grasses.
BONAP Distribution Map

Colorado Status:
Native
Scientific Name Astragalus hallii USDA PLANTS Symbol ASHA2
Common Name Hall's Milkvetch ITIS Taxonomic Serial No. 25531
Family Fabaceae (Pea) SEINet
Reference
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Description Life zones and habitat: Foothills to subalpine (7200 to 10800 ft.); dry, rocky slopes, woodlands, and meadows.
Plant: Ascending or creeping perennial with numerous slender stems up to 2 feet long.
Leaves: Pinnately-compound leaves up to 4 inches long, each with 11 or more small elliptic-oblong or oblanceolate leaflets less than 1/4 to about 1/2-inch long with rounded tips; blades folded nearly in half.
Inflorescence: Small racemes of 10 or more purple-to-lavender/white pea-like flowers; calyx tube reddish to purple with grey or black hairs.
Bloom Period: June to August.
References: www.americansouthwest.net, Wildflowers of Peak 7 and "Flora of Colorado" by Jennifer Ackerfield.
BONAP Distribution Map
Colorado Status:
Native
Scientific Name Astragalus laxmannii var. robustior USDA PLANTS Symbol ASLAR
Common Name Prairie Milkvetch ITIS Taxonomic Serial No. 566195
Family Fabaceae (Pea) SEINet
Reference
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Description Life zones and habitat: Plains to subalpine (4000 to 10500 ft.); sandy soils and rock outcrops in prairies, open forests and mountain meadows.
Plant: Erect, tufted or decumbent perennial with numerous stems 4 to 12 inches tall.
Leaves: Alternate, , pinnately-compound leaves 1-1/2 to 6 inches long, each with 11 to 21 narrowly elliptic-lanceolate to oblong leaflets 3/8 to 1 inch long; upper surface smooth or covered with appressed hairs, lower surface hairy.
Inflorescence: Dense, head-like or spike-like raceme arising on stalks 2 to 6 inches long from leaf axils; head with 15 to 50 short-stalked, ascending, pea-like flowers with blue-lavender to white corollas, 1/2 to almost 3/4-inch long; calyces have appressed black and white hairs, and sharply-pointed teeth from 1/3 as long to as long as the calyx tubes.
Bloom Period: June to August.
References: "Flora of Colorado" by Jennifer Ackerfield and E-Flora-BC.
BONAP Distribution Map
Colorado Status:
Native
Scientific Name Astragalus shortianus USDA PLANTS Symbol ASSH3
Common Name Short's Milkvetch ITIS Taxonomic Serial No. 25678
Family Fabaceae (Pea) SEINet
Reference
Click Here
Description Life zones and habitat: Plains and foothills (4500 to 9800 ft); dry, gravelly areas, shrublands, grasslands, rocky slopes.
Plant: Short perennial up to 6 inches tall; inflorence supported on peduncles rather than stems.
Leaves: Pinnately-compound leaves with 9 to 17 obovate leaflets 1/4 to 3/4-inch long, densely covered with silver hairs.
Inflorescence: Small racemes of purple pea-like flowers in a hairy cluster on peduncles 1 to 6 inches long.
Bloom Period: April to June.
References: www.easterncoloradowildflowers.com, Montana Field Guides and "Flora of Colorado" by Jennifer Ackerfield
BONAP Distribution Map Colorado Status:
Native


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© Tom Lebsack 2021