Ontario Weeds: Creeping yellow cress
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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
- Leaves
- Flowers and Fruit
- Habitat
- Similar Species
- Related Links
Name: Creeping yellow cress, Rorippa
sylvestris (L.) Bess.,
Other Names: rorippe sylvestre
Family: Mustard Family (Cruciferae)
General Description: Perennial, reproducing
by rhizomes and by seed.

Stems & Roots: Spreading or ascending
10-60cm (4-24in.) high, simple to freely branched;
Leaves: Thin and pinnately parted almost
to midrib, lanceolate in outline, with toothed or cut divisions
that are lanceolate or linear; lower leaves up to 20cm (8in.) long,
upper ones progressively reduced;
Flowers & Fruit: Flowers in small
clusters at ends of branches; the clusters expanding into elongated,
open racemes as the flowers mature; each flower 3-10mm (1/8-2/5in.)
wide, with 4 bright yellow petals longer than the 4 sepals; seedpods
(siliques) slenderly linear-cylindric, 2-15mm (1/12-3/5in.) long
and 0.4-1.5mm (1/50-1/16in.) wide; their pedicels 3-20mm (1/8-4/5in.)
long, thread-like and spreading perpendicular to the stem; seeds
0.6-0.8mm (1/40-1/30in.) long. Many patches of Creeping yellow cress
do not set seed and their seedpods remain undeveloped. Flowers from
June to September.
Habitat: Creeping yellow cress was
introduced from Eurasia and is found throughout southern Ontario
in moist soil in river beds, along sand dunes, wet meadows and in
depressional areas in fields and gardens.
Similar Species: It is distinguished by
its perennial habit of growth often resulting in dense patches with
numerous intertwining rhizomes, its petals being much longer than
its sepals, its lateral leaf segments often being sharply toothed
and more widely spaced than in Marsh yellow cress, and the frequent
absence of seed set.
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:
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E-mail: ag.info.omafra@ontario.ca