Ministry of Agriculture, Food and Rural Affairs

Ontario Weeds: Common peppergrass

Table of Contents

1. Name
2. Other Names
3. Family
4. General Description
   • Photos and Pictures
5. Stems and Roots
6. Leaves
7. Flowers and Fruit
8. Habitat
9. Similar Species
10. Related Links

Name: Common pepper-grass, Lepidium densiflorum Schrad.,

Other Names: Green-flowered pepper-grass, Pepperweed, lépidie densiflore, passerage, passerage densiflore

Family: Mustard Family (Cruciferae)

  General Description: Annual or winter annual, reproducing only by seed.

Photos and Pictures

Common peppergrass. A. Root. B. Stem with 4 racemes of seedpods. C. Seedling, top and sideviews. D. Young plant.

Stems & Roots: 10-60cm (4-24in.) high, usually very much-branched in the upper part and sometimes towards the base as well, densely covered with very short hair.

Leaves: Rosette leaves with a definite stalk, deeply lobed or divided into separate segments or merely sharply toothed; lower stem leaves alternate (1 per node), smaller and less lobed than the basal ones; upper stem leaves very narrow and either shallowly toothed or without teeth.

Flowers & Fruit: Flowers individually very small with the white petals extremely short or absent altogether, densely packed in light green clusters at the tips of the branches; seedpods very dense (9 to 15 pods per lcm, 2/5in., of stem), flattened nearly round, 2-3mm (1/12-1/8in.) across with very narrow short narrow short wings towards the tip, a notch between them and a tiny stigma in that notch; seeds 2 per pod, 1 on each side of the septum (membranous partition); septum very narrow, only as wide as the fruit is thick; seeds bright reddish-yellow. Flowers from June to August. When mature, the plant becomes brittle and easily breaks off, rolling and scattering its seed.

Habitat: Common pepper-grass occurs throughout Ontario, being a very common weed in cultivated fields, farmyards, gardens, roadsides and waste areas.

Similar Species: It is distinguished from similar plants by its very numerous, small, rounded but flat, 2-seeded pods with almost no wings around the margins, and the flowers with tiny white petals shorter than the sepals or missing altogether.

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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