Host an Event Volunteer Join Tickets

Support the plant database you love!

Share

Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

Enter a Plant Name:
Or you can choose a plant family:

Astragalus coltonii

Astragalus coltonii M.E. Jones

Colton's Milkvetch

Fabaceae (Pea family)

Synonym(s):

USDA Symbol: ASCO8

USDA Native Status: L48 (N)

"Variably but usually sparsely leafy, sometimes apparently leafless and jun- ceous, strigulose with straight, appressed, filiform or somewhat flattened hairs, the herbage green or cinereous; stems arising from a subterranean root-crown (as typical of the section) or rarely (in A. c. var. Coltoni) from divisions of an aerial, eventually suffruticulose caudex, usually several or numerous, erect and ascending in clumps, 1-4 dm. long, naked and purplish at base, branched or spurred at base or at 1-3 nodes preceding the first peduncle, the branches sometimes disposed in unequal pairs (threes) to an axil, or (upward) inserted between a peduncle and its subtending leaf." (bibref: 1813).

"The species is extremely variable, especially in the development of the foliage, and consequently in gross aspect. The differences in flower-size, width of the pod, and position of the root-crown, once thought (Barneby, 1944, p. 49) sufficient to separate A. canovirens (= A. c. var. moabensis) from genuine A. Coltoni at the specific level, have failed to pass the test's of observation in the field and study of more material. The calyx and petals are now known to vary within nearly the same limits in both supposed species, the known extremes in both directions having been secured from populations of var. Coltoni in the type-region along the Price River. The average pod of A. c. var. moabensis is perhaps a little broader, but it varies considerably in length and girth. The position of the caudex depends, in the case of A. Coltoni, on environment of the individual plant. On rocky slopes or rock ledges the caudex is exposed, apparently more by weathering than by nature, and may become decidedly woody with lapse of time. But on hills of soft clay or on cobblestone bluffs, otherwise similar plants have the buried root- crown or caudex characteristic of var. moabensis and other members of the section. Typical A. c. var. moabensis is distinguished, unless depauperate, by having the proper stem longer in proportion to the more robust lower peduncles, and usually also by its more numerous and better-developed leaflets. However in San Juan and Grand Counties, Utah, and especially at low elevations in the trough of the Grand River, the terminal leaflet may vary from one plant to the next in a small group, now distinctly petiolulate and now clearly decurrent, but often separated from the rachis by a strangulation or a barely perceptible change in texture. Collections from the neighborhood of Cane Springs (e.g., Barneby 12,757), close to the probable type-locality of A. c. var. canovirens, are intermediate in all the critical characters, some individuals leaning toward A. c. var. Coltoni as ideally conceived, others closely approaching typical A. c. var. moabensis." (bibref: 1813).

 

From the Image Gallery

No images of this plant

Plant Characteristics

Duration: Perennial
Habit: Herb
Leaf Arrangement: Alternate
Fruit Type: Legume
Size Notes: "Stems arising from a subterranean root-crown (as typical of the section) or rarely (in A. c. var. Coltoni) from divisions of an aerial, eventually suffruticulose caudex, usually several or numerous, erect and ascending in clumps, 1-4 dm. lo
Leaf: "Stipules 1-7 mm. long, dimorphic, the lowest papery, pallid or brownish, approximate or sometimes imbricated, strongly adnate to a vestigial petiole to form a subtruncate or bidentate sheath, decurrent around 1/2 to the whole stem's circumference but free, the upper ones smaller, herbaceous, obscurely adnate, with deltoid or triangular-acuminate, often spreading or deflexed blades; leaves 2-10 cm. long, variable according to the var., either all imparipinnate, or all (or nearly all) reduced to the naked rachis." (bibref: 1813).
Flower: "Peduncles erect or strictly incurved-ascending, (4) 6.5-30 cm. long, the lowest 1-2 usually much longer and stouter than the rest and far surpassing the leaves, the racemes mostly projected well beyond the leafy part of the plant; racemes loosely (2) 5-30-flowered, the axis elongating, (1.5) 3-16 cm. long in fruit; bracts membranous, ovate or lanceolate, 0.5-3.2 mm. long; pedicels at first ascending, 0.8-1.5 mm. long, early arched outward or decurved, sometimes horizontally spreading, in fruit thickened, 1-2.5 mm. long; bracteoles 0, rarely a minute scale; calyx 4.5-8 mm. long, densely to quite thinly black-strigulose, the oblique disc 0.9-1.5 (1.8) mm. deep, the membranous, purplish, deeply campanulate or cylindric tube 4-6.7 mm. long, 2.3-3.7 mm. in diameter, the deltoid, triangular, or broadly subulate, often obtuse teeth 0.6-1.8 (2.3) mm. long, the ventral pair commonly shortest, the orifice strongly or little oblique; petals bright pink-purple, drying bluish, the wing-tips often paler; banner broadly rhombic-elliptic, -obovate, or broadly spatulate, notched or scarcely emarginate, 12-18.5 mm. long, (6) 6.5-12.5 mm. wide; wings as long or a little shorter, 11-18.3 mm. long, the claws 5.3-7.8 mm., the narrowly lanceolate, oblong-elliptic, or -oblanceolate, obtuse, subtruncate, or obliquely emarginate, straight or slightly incurved blades 8.6-11.8 mm. long, 2.3 3.5 mm. wide; keel 9-13 mm. long, the claws 4.9-7.4 mm., the half-obovate or lunately half-elliptic blades 4.6-6.6 mm. long, 2.3-3.5 mm. wide, incurved through 85-95 degrees to the triangular-deltoid, sometimes slightly porrect and subacute apex; anthers (0.55) 0.6-0.9 (1) mm. long." (bibref: 1813).
Fruit: "Pod pendulous, stipitate, the slender stipe 4-11 mm. long, the body oblong, linear-oblong, or -oblanceolate, 1.9-3.5 cm. long, (3) 3.5-6 mm. in diameter, straight or gently decurved, narrowly cuneate at base or tapering gradually downward into the stipe, cuneate-cuspidate at apex, strongly compressed laterally and 2-sided, bicarinate by the subfiliform but salient sutures, the faces low-convex, the somewhat fleshy, green or reddish, glabrous valves becoming stiffly papery, stramineous, almost smooth to faintly rugulose and cross-reticulate; ovules 14-20; seeds brown or olivaceous, sometimes purple- speckled, sparsely punctate, sublustrous, (2.9) 3.2-4.4 mm. long." (bibref: 1813).

Bloom Information

Bloom Color: Pink , Blue , Purple
Bloom Time: Apr , May , Jun
Bloom Notes: "Petals bright pink-purple, drying bluish." (bibref: 1813).

Distribution

USA: AZ , CO , NM , UT , WY
Native Distribution: As given for the varieties. (bibref: 1813).
Native Habitat: As given for the varieties. (bibref: 1813).

Bibliography

Bibref 1813 - Atlas of North American Astragalus (1964) Barneby, Rupert C.

Search More Titles in Bibliography

Additional resources

USDA: Find Astragalus coltonii in USDA Plants
FNA: Find Astragalus coltonii in the Flora of North America (if available)
Google: Search Google for Astragalus coltonii

Metadata

Record Modified: 2020-12-07
Research By: Joseph A. Marcus

Go back