Vascular Plants - Caryophyllaceae - Scleranthus:
Scleranthus annuus
Page Author: David Giblin
annual knawel, German knotgrass 
Blooms: April-July
Habit: herb
Duration: annual
Origin: Introduced from Europe
Distribution: Occasional introductions throughout the Pacific Northwest
Habitat: Disturbed soils, waste lots, cultivated areas.
Species 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.
Synonyms:
(none)

Treated in Flora of the PNW as:
Scleranthus annuus
Additional Resources:

PNW Herbaria Specimens: View list of all Scleranthus annuus specimens in the Consortium of Pacific Northwest Herbaria database.

WTU Herbarium Specimens: View list of Scleranthus annuus specimens in the WTU Herbarium database.

Washington Flora Checklist: Scleranthus annuus treatment.

E-Flora BC: Scleranthus annuus atlas page.

CalPhotos: Scleranthus annuus images.

USDA Plants Database: Scleranthus annuus.
Additional photographs of Scleranthus annuus:
(click on a thumbnail to view larger photo)

Ben Legler, 2004

Ben Legler, 2004

Ben Legler, 2004

Ben Legler, 2005

Ben Legler, 2005

Ben Legler, 2005

Ben Legler, 2005

G. D. Carr, 2009

G. D. Carr, 2009

G. D. Carr, 2009

G. D. Carr, 2009

Paul Slichter, 2009

Paul Slichter, 2009

Paul Slichter, 2009

G. D. Carr, 2011

G. D. Carr, 2011

G. D. Carr, 2011

G. D. Carr, 2011

Robert L. Carr, 2011

Robert L. Carr, 2011

Robert L. Carr, 2011
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