Page author: David Giblin
Scleranthus annuus
annual knawel
Specimens
Photos

Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Saskatchewan, Montana, and Idaho; also from the central U.S. to eastern North America.

Habitat: Disturbed soils, waste lots, and cultivated areas.

Flowers: April-July

Origin: Introduced from Europe

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Self-pollination, generalist

Description:
General:

Low, spreading annual, the stems prostrate to ascending, up to 15 cm. long.

Leaves:

Leaves opposite, attached to each other at the base, linear, with a stiff, sharp point, 5-15 mm. long.

Flowers:

Flowers very small, greenish, in a tight, dichotomously-branched inflorescence; calyx bell-shaped, 10-nerved, 3-4 mm. long, the 5 lobes narrowly lanceolate, equaling the tube; petals none; stamens 10, borne on a disk at the top of the calyx tube; styles 2.

Fruits:

Ovoid, 1-celled, 1-seeded utricle enclosed by the hardened calyx tube.

Accepted Name:
Scleranthus annuus L.
Publication: Sp. Pl. 1: 406. 1753.

Synonyms & Misapplications:
(none provided)
Infraspecies:
Additional Resources:

PNW Herbaria: Specimen records of Scleranthus annuus in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Scleranthus annuus checklist entry

OregonFlora: Scleranthus annuus information

E-Flora BC: Scleranthus annuus atlas page

CalPhotos: Scleranthus annuus photos

28 photographs:
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