Cyperus erythrorhizos Muhl.
red-rooted cyperus (redroot flatsedge)
Cyperaceae (Sedge family)

Introduction to Vascular Plants

Photograph

© Province of British Columbia (Brenda Costanzo)     (Photo ID #22450)


Map

E-Flora BC Static Map

Distribution of Cyperus erythrorhizos
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Species Information

General:
Annual, tufted herb from fibrous roots; stems stout, mostly 5-70 cm tall.
Leaves:
Clustered towards the bases; blades well-developed, mostly 2-9 mm wide, elongate, about as long as the stem.
Flowers:
Inflorescence of dense, more or less elongate, head-like clusters, the terminal clusters unstalked, the others on rays up to 7 cm long (or some rays bearing only single spikes), each cluster with numerous, crowded, spirally arranged, cylindrical spikes on the elongate axis of the inflorescence, the spikes 1-4 cm long, the spikelets 6- to many-flowered, 3-12 mm long, 1-1.5 mm wide, slender, horizontally spreading; involucral bracts several, elongate, unequal, sometimes a little wider than the leaves, much surpassing the inflorescence.
Fruits:
Scales obscurely nerved, egg-shaped, closely set, the tips surpassing the ones below them by 0.4-0.7 mm, not recurved, the margins narrow, golden brown, the keels prominent, excurrent, green, 1.2-1.5 mm long; rachillas narrowly translucent-winged, persistent, but the scales eventually falling from them and the wings readily deciduous in short segments at maturity; stamens 3; achenes unequally 3-angled, pale, shining, 0.7-1 mm long.

SourceThe Illustrated Flora of British Columbia

Illustration

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Green
Blooming Period:
Mid Summer
Fruit/Seed characteristics:
Colour: White
Present from Summer to Fall
Source:  The USDA

Habitat and Range

Moist to wet lakeshores in the steppe zone; rare in SC BC; disjunct E to S ON and S to FL, MS, TX, NM, AZ and CA.

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Cyperus halei Torr. ex Britton