Ontario Weeds: Swamp milkweed
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Excerpt from Publication 505, Ontario Weeds,
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Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Roots
- Flowers and Fruit
- Habitat
- Similar Species
- Caution
- Related Links
Name: Swamp milkweed Asclepias incarnata
L.,
Other Names: asclépiade incarnate
Family: Milkweed Family (Asclepiadaceae)
General Description: Perennial, reproducing
by seed and possibly by rhizomes.
Swamp milkweed. B. Flowering stem with 10 simple umbels.
Swamp milkweed. A. Base of plant. C. Two seedpods from 2 flowers of 1 umbel.
Stems & Roots: Stems erect, stout,
30-150cm (12-60in.) high, with little milky juice and few, if any,
hairs; leaves opposite, rather numerous, lanceolate to elliptic,
4.5-20cm (1¾-8in.) long with fine veins clearly visible on
the underside.
Flowers & Fruit: Inflorescence
broad, usually formed from several umbels of flowers; flowers pink
to rose-purple (rarely whitish), similar to those of Common milkweed
but more slender; fruits slender pods with elongated tips, rusty-green,
splitting lengthwise at maturity; seeds brown, flat, with winged
margins and tufts of long, silky, white hair. Flowers from June
to August.
Habitat: Swamp milkweed is found in
swamps, ditches and other wet areas in woods, fields and roadsides
in southern and central Ontario.
Similar Species: It is distinguished from
other milkweeds by its numerous, slender leaves, its pink to rose-purple
flowers and its slender, non-warty pods, and from other narrow-leaved
plants by its smooth stems, slender, opposite leaves and somewhat
milky juice.
Caution: It is considered poisonous to
livestock.
Related Links
... on general Weed
topics
... on weed identification, order OMAFRA
Publication 505: Ontario Weeds
... on weed control, order OMAFRA
Publication 75: Guide To Weed Control
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