Ontario Weeds: Cleavers

Return to the Ontario Weeds Gallery

Excerpt from Publication 505, Ontario Weeds, Order this publication


Table of Contents

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

Name: Cleavers, Galium aparine L.,

Other Names: gaillet grateron, Spring cleavers, Goose-grass, gratteron

Family: Madder Family (Rubiaceae)

General Description: Annual, reproducing only by seed.

Photos and Pictures

Cleavers, showing backward- or downward-pointing hairs on stems and whorled leaves.

Cleavers, showing backward- or downward-pointing hairs on stems and whorled leaves.

Cleavers. A. Lower and upper parts of a mature plant. B. Portion of stem enlarged to show the backward-pointing bristles.

Cleavers. A. Lower and upper parts of a mature plant. B. Portion of stem enlarged to show the backward-pointing bristles.

Stems & Roots: Stems weak or reclining, 10-121cm (4-48in.) long, square in cross-section with strongly ribbed corners, with very short, downward- or backward-pointing, firm, hair-like, curved bristles; leaves usually 3 to 8 in a whorl, linear, tapering at the base, mostly 1-8cm (2/5-3-2/5in.) long, with bristles at the pointed tip, somewhat hairy on both surfaces and with many very short, backward-pointing bristles on the margins. These tiny hook-like bristles on stems and leaves cause them to cling together in masses and to cling to clothing, skin or fur, hence the common name, "cleavers."

Flowers & Fruit: Inflorescence mostly 1- to 5-flowered; flowers very small and soon replaced by the small spherical fruits; fruits bristly, 1.5-4mm (1/16-1/6in.) in diameter. Flowers from May to August.

Habitat: Cleavers is found in southern Ontario in woods, meadows, compost heaps, gardens and fields, and along roadsides and riverbanks.

Similar Species: It is distinguished by its square, weak, clinging stems, its bristle-tipped leaves that also cling with backward-pointing bristles on the margins, and all leaves arranged in whorls of 3 to 8 at each node of the stem.

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

| Back to the Ontario Weeds Gallery |


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca