Ontario
Weeds: Petty spurge
Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Roots
- Flowers and Fruit
- Habitat
- Similar Species
- Related Links
Name: Petty spurge, Euphorbia peplus
L.,
Other Names: euphorbe peplus, euphorbe
des jardins
Family: Spurge Family (Euphorbiaceae)
General Description: Annual, reproducing
only by seed.
Photos and Pictures
Petty spurge, inflorescence viewed from side.
Stems & Roots: Stems erect, 10-30cm
(4-12in.), single or branched from the base; top of each main stem
3-branched at base of inflorescence; lower and middle stem leaves
alternate (1 per node), oblong to rounded, 1-2cm (2/5-4/5in.) long,
short-stalked; leaves at tip of stem in one whorl of 3 leaves from
the same node; leaves opposite (2 per node) in the inflorescence.
Flowers & Fruit: Inflorescence beginning
as a 3-branched umbel and branching repeatedly in 2's, with a small
flower cluster, in the angle between each pair of branches; flowers
complex in cyathia or tiny cups, like those described for Leafy spurge;
seedpods 3-lobed, containing 3 seeds; seeds about 1.5mm (1/16in.)
long and about half as wide, somewhat 6-sided, the 2 inner faces with
long, narrow depressions, the 4 outer surfaces with 2 to 4 circular
depressions, gray to gray-brown. All parts contain a white milky juice
which freely exudes when the plant is cut or broken. Flowers from
early July until end of fall.
Habitat: Petty spurge occurs throughout
southern Ontario in gardens, waste areas, roadsides and occasionally
in cultivated fields.
Similar Species: It is distinguished from
other erect-growing spurges by its annual habit, by the combination
of alternate leaves on main stem, whorl of 3 leaves at tip of stem,
and pairs of smaller opposite leaves in the inflorescence, by its
main umbel at the tip of the stem having only 3 branches, and by its
small, elongated, gray to brownish, 6-sided seeds with 2 elongated
depressions and 4 rows of 2 to 4 rounded depressions. There is also
a tendency for the stems to be somewhat succulent, and for the 3 main
branches of the inflorescence to be somewhat enlarged above the nodes
and taper upwards to be much thinner just below the next pair of small
leaves.
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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