E-Flora BC: Electronic Atlas of the Flora of British Columbia

Asclepias speciosa Torr.
showy milkweed
Apocynaceae (Dogbane family)
(Previously in Asclepiadaceae)

Introduction to Vascular Plants

© Brian Klinkenberg  Email the photographer   (Photo ID #6852)

E-Flora BC Static Map
Distribution of Asclepias speciosa
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Species Information

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Perennial herb from a rhizome; stems erect, 0.4-1.2 m tall, woolly, greyish or glabrous below; plants with milky juice.
Opposite, simple, 10-20 cm long, fleshy, oblong or oval, rounded or heart-shaped at the base, stalked.
Inflorescence an umbrella-like cluster; flowers pink to reddish-purple; sepals greenish-tinged with red.
Cylindric pods with soft tubercules, 7-11 cm long, many-seeded with tufts of white cottony hairs; seeds flattened, wrinkled.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Early Summer
Fruit/Seed characteristics:
Colour: Black
Present over the Summer
Source:  The USDA

Habitat / Range

Moist to mesic roadsides, ditches, streamsides, meadows and grasslands in the steppe and montane zones; common in SC and SE BC; E to MB and S to MO, TX and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Asclepias speciosa

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




Elevation (metres) 296 425 600
Slope Gradient (%) 0 4 34
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
200 219 240
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 3 6
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BG(9)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Asclepias giffordii Eastw.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References