Ontario Weeds: Wild mustard
Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Roots
- Leaves
- Flowers and Fruit
- Habitat
- Similar Species
- Related Links
Name: Wild mustard,
Sinapis arvensis
L.,
Other Names: Charlock, Common mustard,
Field mustard, Herrick, Kale, Mustard, Yellow mustard, moutarde des
champs, moutarde sauvage, sénevé,
Brassica kaber
(DC.) L.C. Wheeler var.
pinnatifida (Stokes) L.C. Wheeler.
Family: Mustard Family (Cruciferae)
General Description: Annual, reproducing
only by seed.
Photos and Pictures
Wild mustard (A - plants; B - flowers and seedpods).
Wild mustard. A. Base of plant. B. Flowering stem. C.
Seedpod. D Young plant. E. Seedling, top and side views. F. Seedling
with 2 true leaves.
Stems & Roots: Stems erect, 20-90cm
(8-36in.) high, branching in the upper part, harshly hairy near
the base but weakly hairy or smooth upwards, greenish or sometimes
purplish.
Leaves: Seedling with broad kidney-shaped
cotyledons; stem leaves alternate (1 per node), somewhat hairy;
lowermost leaves on young plants long-stalked and either without
lobes or with shallow to deep lobes near the base of the blade;
upper leaves stalkless and coarsely toothed but usually not lobed.
Flowers & Fruit: Flowers in small
clusters which lengthen as the seedpods develop, bright lemon yellow,
about 1.5cm (3/5in.) across with 4 small sepals, 4 larger petals
arranged in the form of a cross (Family name "Cruciferae"
means crucifix or cross), 4 long and 2 short stamens (total 6) and
1 slender pistil; flower stalks thin and short (3-5mm, 1/8-1/5in.
long), becoming thicker but not longer as the seedpods develop,
sometimes nearly as thick as the pod itself; seedpods (siliques)
3-5cm (1¼-2in.) long, sometimes bristly hairy but usually
without hair, often with lengthwise ribs, erect and pressed to the
stem or spreading out; each pod has a flattened terminal beak with
1 or rarely 2 seeds in its base and a main section containing several
seeds which are released when the 2 sides or valves split apart
from the bottom end and fall away entirely; seeds spherical, 1.5mm
(1/16in.) in diameter, black or purplish. Flowering may begin as
early as late May and continue throughout the summer.
Habitat: Wild mustard occurs throughout
Ontario, being most frequent in cultivated fields and gardens, but
occasionally appearing in fence lines, along roadsides and in waste
areas.
Similar Species: It is distinguished
from similar mustards by its somewhat kidney-shaped cotyledons being
broad with a deep, wide, rounded notch at the end, the hairy stem
with lower leaves stalked and either lobed or unlobed but upper
ones stalkless and merely toothed, its large flowers and its seedpod
with a short thick stalk and a flat beak that is about 1/3 the total
length of the pod and usually contains an additional seed or two;
and from Yellow rocket by being annual with hairy stems, its lemon-yellow
flowers usually not appearing before late May and its seedpods on
short, thick stalks and having a prominent, flat beak containing
1 or 2 seeds.
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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