Ontario Weeds: Jimsonweed
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Excerpt from Publication 505, Ontario Weeds, Order this publication
Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Roots
- Flowers and Fruit
- Habitat
- Similar Species
- Caution
- Related Links
Name: Jimsonweed, Datura stramonium
L.,
Other Names: stramoine commune, Stinkweed,
Thornapple, pomme épineuse, herbe du diable
Family: Nightshade or Potato Family (Solanaceae)
General Description: Annual, reproducing
only by seed.
Jimsonweed (A - plant beginning to flower; B - portion of stem with spiny seedpods).
Jimsonweed. A. Top of flowering plant. B. Seedling. C.
Fruit.
Stems & Roots: Stems stout, erect,
90-200cm (3-6½ft) high, usually much-branched in the upper
part, smooth and hairless, larger plants with the main stem often
5cm (2in.) or more in diameter; cotyledons (seed leaves) long-oval,
2-4cm (4/5-1½in.) long, shriveling but persisting on the
developing seedling; first true leaves ovate with pointed tips and
few or no lobes; later leaves distinctly alternate (1 per node),
usually somewhat coarsely and sharply toothed or lobed, 10-20cm
(4-8in.) long and long-stalked.
Flowers & Fruit: Flowers and seedpods
short-stalked, borne singly in the angles between 2 or more stems
and a leaf; calyx tubular or urn-shaped; corolla white or light
purple, very long, tubular or trumpet-shaped, 7-10cm (3-4in.) long,
the flared end with 5 points; seedpod at first green and fleshy
with sharp, soft spines, becoming a large (2-5cm, 4/5-2in. across),
dry, hard seedpod covered with very sharp, harsh spines and containing
numerous black, flat, round seeds. Flowers from July to autumn.
Habitat: Jimsonweed occurs in the warmer
parts of southern Ontario in cultivated fields and around farmyards.
Similar Species: It is distinguished by
its tall, stout, branched stem (like small trees), large leaves,
large, white or purplish trumpet-shaped flowers, large spiny seedpod
and sour repulsive odour.
Caution: The whole plant has a sour repulsive
odour and all parts of the plant are poisonous.
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