Ontario Weeds: Yellow avens
Table of Contents
- Name
- Other Names
- Family
- General Description
- Stems and Roots
- Flowers and Fruit
- Habitat
- For more information...
Name: Yellow avens, Geum aleppicum
Jacq. var. strictum (Ait.) Fern.,
Other Names: Benoîte stricte, Burs,
benoîte d'Alep
Family: Rose Family (Rosaceae)
General Description: Perennial, reproducing
only by seed. It is distinguished in the rosette stage by longstalked,
pinnately compound leaves, each with a large terminal leaflet and irregularly
sized and shaped lateral leaflets; and in the flowering and fruiting stages,
by its variable leaves, its deep yellow to orange-yellow flowers and the
brown spherical, burlike clusters of seeds, each with a long hooked beak
that will cling to skin and clothing.
Photos and Pictures
Yellow avens.
Stems & Roots: Stems erect, to 1 m (40
in.) high, frequently branched above. Leaves very variable, rosette leaves
long-stalked, pinnately compound with a large terminal leaflet and a mixture
of large and small leaflets along each side of the central stalk (rachis),
leaflets coarsely toothed, hairy and green on both surfaces; stem leaves
alternate (1 per node), similar but with shorter stalks, especially towards
the top of the stem and each with a pair of green leaflet-like stipules
where the leafstalk joins the stem; upper leaves stalkless, sometimes
just shallowly toothed or lobed without being divided into leaflets.
Flowers & Fruit: Flowers few in widely
branching inflorescences, 1 - 2 cm (2/5 - 4/5 in.) across, with 5 deep
yellow to orange-yellow petals, 5 smaller sepals, numerous stamens and
pistils in a dense central cluster; at maturity each flower stalk lengthening
and the cluster of pistils enlarging into a nearly spherical brown to
dark brown head or bur about 2 cm (4/5 in.) in diameter; each single-seeded
pistil (now a fruit or "seed") in the mature bur has a sharply
hooked tip which clings to fur, clothes and skin. Flowers from early June
to late summer, and the burs persist into late fall or winter.
Habitat: Yellow avens occurs throughout
Ontario in meadows, open woods, pastures, waste areas and roadsides, but
is rarely found in cultivated land.
For more information...
... on weed identification, order OMAFRA
Publication 505: Ontario Weeds
... on weed control, order OMAFRA
Publication 75: Guide To Weed Control
...on weeds in field crops, contact Mike Cowbrough (mike.cowbrough@ontario.ca),
Weed Management Specialist (Field Crops), OMAFRA
...on weeds in horticultural crops, contact Kristen Callow (kristen.callow@ontario.ca),
Weed Management Specialist (Hort Crops), OMAFRA
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