Ontario Weeds: Clasping-leaved dogbane
Return to the Ontario Weeds Gallery
Excerpt from Publication 505, Ontario Weeds, Order this publication
Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Roots
- Leaves
- Flowers and Fruit
- Habitat
- Similar Species
- Caution
- Related Links
Name: Clasping-leaved dogbane Apocynum
sibiricum Jacq.,
Other Names: apocyn a feuilles embrassantes,
Indian hemp, Prairie dogbane, chanvre sauvage
Family: Dogbane Family (Apocynaceae)
General Description: Resembles both
Spreading
dogbane and Indian hemp and before flowering is easily confused
with Common
milkweed. Perennial from deeply penetrating and widely spreading
coarse roots, these often 20-30cm (8-12in.) below the surface.
Clasping-leaved dogbane, showing deep perennial root from which 4 shoots emerged.
Clasping leaved dogbane. C. 3 shoots forma deep, coarse perennial root (dotted line represents ground surface), and leaves on lower portion of 1 shoot.
Stems & Roots: Stems coarse,
erect, up to 1m (40in.) tall, arising from buds on the roots; the
main stem with branches throughout its length, smooth and hairless,
green or with a slight pinkish cast.
Leaves: Leaves usually opposite but
occasionally alternate, mostly sessile or with very short petioles
(usually not more than 3-5mm, 1/8-1/5in. long), up to 5cm (2in.)
wide and 12cm (4¾in.) long or sometimes larger, oblong to
broadly elliptic with a somewhat abruptly pointed tip and a broadly
rounded to heart-shaped base, smooth and hairless on both surfaces,
the undersurface lighter green than the upper; the basal lobes of
the larger leaves somewhat clasping the stem.
Flowers and Fruit: Inflorescence,
flowers and seedpods similar to those of Spreading dogbane except
that the calyx lobes of Clasping-leaved dogbane are narrow and 3-5
times longer than wide, and its corolla is white and usually only
3-6mm (1/8-¼in.) long. All parts of the plant contain milky
juice. Flowers from July to September.
Habitat: Clasping-leaved dogbane is
also a native plant with much the same distribution and abundance
as Spreading dogbane
Caution: May be 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
For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca