Astragalus canadensis L.
Canadian milk-vetch (Canada milk-vetch; Canadian milkvetch)
Fabaceae (Pea family)
Introduction to Vascular Plants
Canadian milk-vetch (Canada milk-vetch; Canadian milkvetch)
Fabaceae (Pea family)
Introduction to Vascular Plants
Photograph
© Eileen Brown (Photo ID #9939)
Species Information
General:
Robust perennial herb from a spreading rhizome, greenish and nearly glabrous to greyish with basally 2-forked hairs; stems 1-few together, erect to decumbent, simple or branched above, 0.3-1 m tall.
Leaves:
Alternate, pinnately compound, 10-20 (35) cm long; leaflets 13 to 29, elliptic to oblong, blunt or notched and tiny-pointed at the tip, 1.5-4 cm long, often glabrous above; stipules membranous-papery, 6-15 mm long, some or all fused and sheathing at the base, the free ends lanceolate and long-tapering.
Flowers:
Inflorescence a spike-like, axillary raceme of 30 to 150, nodding, downward overlapping, pea-like flowers, the racemes 5-15 cm long on stalks 5-20 cm long; corollas greenish-white to cream, 12-17 mm long, the wings equal to the banner, the keel often purple-tipped; calyces 6-10 mm long, finely appressed-hairy, the tube twice as long as the awl-shaped teeth.
Fruits:
Pods, erect on stubs 1-2 mm long, crowded and persistent on the erect stalk of the inflorescence, cylindric, 8-20 mm long, with a tiny hook at the tip, somewhat leathery or stiff-papery, often finely appressed-hairy, 2-chambered.
Notes:
Three varieties are recognized for BC. The two varieties in S BC are sympatric and freely intergradient.
1. Pods cylindric, not grooved beneath and usually hairless; plants of NE BC..................... var. canadensis
1. Pods grooved beneath and usually hairy; plants of S BC.
2. Calyces white- and black-hairy; the teeth nearly equal in size, 1.5-3 mm long; plants greenish, not silvery-hairy...................... var. mortonii (Nutt.) S. Wats.
2. Calyces white-hairy, the teeth 1-2 mm long, the upper pair broader and shorter than the lower three; plants more or less silvery-hairy.....................var. brevidens (Gandog.) Barn.
USDA Species Characteristics
Flower Colour:
White
Blooming Period:
Mid Summer
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source: The USDA
Ecology
Ecological Framework for Astragalus canadensis
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)
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) |
968 | 34 | 1768 |
| Slope
Gradient (%) |
8 | 0 | 73 |
|
Aspect (degrees) |
246 | 0 | 360 |
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
4 | 1 | 7 |
| Modal
Nutrient Regime
Class |
D | ||
| #
of field plots species was recorded in: |
41 | ||
| Modal
BEC Zone Class |
IDF | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
BG(4), BWBS(7), ESSF(3), ICH(4), IDF(9), MS(2), PP(1), SBPS(3), SBS(3) | ||
|
Source:
Klinkenberg 2013
|
|||
Habitat and Range
Mesic to dry open forests, thickets, meadows, streambanks and lakeshores in the steppe and montane zones; common in NE BC (var. canadensis) and S BC east of the Coast-Cascade Mountains (vars. brevidens and mortonii); var. canadensis - N to NT, E to PQ and S to AR, VA and TX, var. brevidens - S to SD, ND, CO and CA, var. mortonii - S to ID, MT and N WA.Status Information
| Scientific Name | Origin Status | Provincial Status | BC List (Red Blue List) | COSEWIC |
|---|---|---|---|---|
| Astragalus canadensis var. brevidens | Unknown/Undetermined | SU | Unknown | Not Listed |
| Astragalus canadensis var. canadensis | Native | S5 | Yellow | Not Listed |
| Astragalus canadensis var. mortonii | Native | S5 | Yellow | Not Listed |
BC Ministry of Environment: BC Species and Ecosystems Explorer.