Ontario Weeds: Yellow rocket
Table of Contents
- Scientific name
- Other names
- General description
- Flowers and fruit
- Often confused with / Distinguishing features
- Herbicide resistance
- For more information...
Herb barbara, Herb of St. Barbara, Winter cress, barbarée vulgaire, herbe de Sainte-Barbe, cresson d'hiver
Mustard Family (Cruciferae)
Usually biennial or perennial, but some plants flower, set seed and die after their first growing season; reproducing only by seed.
Yellow rocket is common throughout most of Ontario in meadows, pastures, waste areas, roadsides, railways and along watercourses. It is especially common in moist rich soil and is apparently still spreading rapidly in such areas. Its occurrence in grain fields is increasing.
- Stems form in the spring
- 1 to several stems per plant
- Stem is erect, 20 - 80 cm high
- Young plants produce a rosette of smooth, shiny, dark green
leaves during the first year
- Leaves stay green throughout the winter and may turn slightly
purple by spring
- Leaves are long-stalked, hairless and divided into one rounded
terminal lobe with several smaller lobes along each side
- Upper leaves are alternate (one per node), short-stalked or
- Upper leaves are coarsely toothed (or without teeth), or sometimes deeply lobed but always with a pair of basal lobes which clasp the stem
Flowers & fruit:
- Flowers are golden-yellow and 10-16 mm across
- Seedpods and their stalks either nearly erect and overlapping one another forming a dense raceme
- Or the stalks spread with the seedpods standing outwards or curving upwards and usually not overlapping one another, forming an open raceme
- Stalks are usually 3-6 mm long, pods 1.5-3 cm long with a slender, seedless beak 2-3 mm long
- Seeds egg-shaped 1-1.5 mm long and a metallic gray-brown colour
- Flowers from mid-May to early July and sometimes again briefly
in late autumn.
Yellow rocket is often mistaken for wild mustard. Yellow rocket is a perennial or biennial, so flowers much earlier in the season than wild mustard and has smaller and deeper golden-yellow flowers. Its leaves are dark glossy green or somewhat purplish, hairless, and distinctly clasp the stem, and the seedpod is tipped by a very slender beak which does not have a seed in its base.
No documented cases of herbicide resistance to date.
Figure 1. Yellow rocket seedling
Figure 2. Leaf of yellow rocket with basal lobe clasping the stem
Figure 3. Flowers of yellow rocket
Figure 4. Yellow rocket whole plant
... on weed identification, order OMAF
and MRA Publication 505: Ontario Weeds
... on weed control, order OMAF and MRA Publication 75: Guide To Weed Control
...on weeds in field crops, contact Mike Cowbrough (email@example.com), Weed Management Specialist (Field Crops), OMAF and MRA
...on weeds in horticultural crops, contact Kristen Callow (firstname.lastname@example.org), Weed Management Specialist (Hort Crops), OMAF and MRA
For more information:
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