Astragalus robbinsii (Oakes) A. Gray
Robbins' milk-vetch
Fabaceae (Pea family)

Introduction to Vascular Plants

Photograph

© Paul Handford     (Photo ID #72754)


Map

E-Flora BC Static Map

Distribution of Astragalus robbinsii
Click here to view the full interactive map and legend

SUBTAXA PRESENT IN BC

Astragalus robbinsii var. minor

Species Information

General:
Perennial herb from a taproot and branching stem-base; stems usually ascending to erect but decumbent-based, sometimes prostrate on harsh sites, 20-70 cm tall/long, with short, stiff, appressed, unbranched hairs or nearly glabrous.
Leaves:
Alternate, pinnately compound, 5-12 cm long; leaflets 7 to 19, narrowly egg-shaped to oblong, rounded or notched at the tip, 1-3 cm long, glabrous above, paler and short-hairy on the lower surface; stipules egg-shaped, 4-7 mm long, the lower ones joined and clasping the stem.
Flowers:
Inflorescence a loose, axillary raceme of 6 to 25 or more pea-like flowers mostly on one side of the axis, the raceme-stalks 9-23 cm long, longer than the leaves; corollas whitish or yellowish to pale purple, fading bluish, 6-11 mm long, the banner much longer than the wings, which are longer than the keel; calyces bell-shaped, 4-7 mm long, short-black-hairy, the lance-linear teeth 1/4-1/2 the length of the tube.
Fruits:
Pods, narrowly ellipsoid, spreading to drooping, short-stalked, membranous, black-hairy, 1.5-2.5 cm long, compressed, 1-chambered but with a thin partial partition.

SourceThe Illustrated Flora of British Columbia

Ecology

Ecological Framework for Astragalus robbinsii

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Avg

Min

Max

Elevation (metres)
1950 1000 2682
Slope Gradient (%)
38 0 95

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

227 20 355
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 0 5
Modal Nutrient Regime
Class
C
# of field plots
 species was recorded in:
26
Modal BEC Zone Class
ESSF

All BEC Zones (# of stations/zone) species was recorded in

BG(1), BWBS(1), ESSF(12), ICH(1), IDF(2), IMA(5), MS(2), SWB(1)

Habitat and Range

Moist to mesic meadows, streambanks, gravel bars, rocky slopes and forest openings in the steppe and montane zones, rarely to the alpine zone; frequent in BC S of 52degreeN and east of the Coast-Cascade Mountains; N to AK, YT and NT, E to SW AB and S to CO, NV and N WA.

SourceThe Illustrated Flora of British Columbia