Ontario Weeds: Three-seeded mercury
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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
- Related Links
Name: Three-seeded mercury, Acalypha
rhomboidea Raf.,
Other Names: ricinelle rhomboide, Copperleaf,
rhombic copperleaf, ricinelle de Virginie
Family: Spurge Family (Euphorbiaceae)
General Description: Annual, reproducing
only by seed.
Three-seeded mercury. A. Plant. B. Portion of fruiting stem
showing 1 three-seeded fruit developing from 1 of 4 flowers in a
leaf axil.
Stems & Roots: Stems erect, 7.5-100cm
(3-40in.) high, simple or branched, slightly hairy; leaves green
to bronze-green, 1-9cm (2/5-3½in.) long, lance- to rhombic-ovate
on petioles that are 1/3 the length to almost as long as the leaf
blade; margins with irregular, rounded teeth.
Flowers & Fruit: Flowers in greenish
clusters in axils of leaves, each cluster composed of one or more
palmately cleft bracts with 5 to 9 lobes, one or more stalked male
spikes 4-15mm (1/6-2/5in.) long and one or more shorter female flowers;
seedpods deeply 3-lobed (similar to those of Leafy spurge) and containing
3 seeds; seeds tan coloured, 1.6-1.8mm (1/15in.) long. Flowers from
July to September.
Habitat: Three-seeded mercury occurs
in dry or moist soil in open woods, fields, waste places, ditches
and roadsides throughout south-central Ontario.
Similar Species: It resembles young plants
of Redroot
pigweed but is distinguished by its flowers borne in axillary
clusters with bracts having 5-9 lobes and its leaves occasionally
a bronze-green colour.
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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