Page authors: David Giblin, Don Knoke
Asclepias speciosa
showy milkweed

Distribution: Occurring east of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to Mexico, east to the Great Plains and Great Lakes region.

Habitat: Riparian corridors, irrigation ditches, roadsides, and other at least seasonally wet areas at low elevations, often in loam soils.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bumblebees, bees, butterflies, beetles, wasps


Perennial herb from widespread rhizomes, the stems 4-12 dm. tall, gray-woolly throughout, the juice milky.


Leaves opposite, petiolate, oblong-lanceolate to ovate-oblong, 10-20 cm. long and up to 10 cm. broad, transversely veined


Inflorescence of several umbels with peduncles 3-8 cm. long and pedicels 1-3 cm. long; sepals 5, greenish, tinged with red; petals about 1 cm. long, pink to purplish-red; stamens 5, attached to the base of the corolla tube and to each other, forming a column, to which are attached saccate structures considerably longer that the petals, pink, with incurved projections; pistil 1, 2-carpellary, the ovaries superior and distinct.


Follicles narrowly ovoid, warty, 7-11 cm. long, the seeds flattened, rough, 8 mm. long.

Accepted Name:
Asclepias speciosa Torr.
Publication: Ann. Lyceum Nat. Hist. New York 2: 218-219. 1827.

Synonyms & Misapplications:
Asclepias giffordii Eastw.
Additional Resources:

PNW Herbaria: Specimen records of Asclepias speciosa in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Asclepias speciosa checklist entry.

OregonFlora: Asclepias speciosa information.

E-Flora BC: Asclepias speciosa atlas page.

CalPhotos: Asclepias speciosa photos.

USDA Plants: Asclepias speciosa information.

89 photographs:
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