Cyperus squarrosus L.

Awned Flatsedge

• State Rank: S2
• Global Rank: G5
• State Status: Special Concern

Habitat: Damp sands, silts, and alluvium [Non-tidal river shore (non-forested, seasonally wet)]

Range: New Brunswick and Maine, south to Florida, west to Texas, north to British Columbia.

Aids to Identification: Members of this genus can be difficult to identify without careful examination of microscopic features and an overall knowledge of the group. Cyperus species are identified by their 2-ranked scales of spikes, triangular stems, terminal inflorescences, and styles deciduous from the achene. Cyperus squarrosus is an annual with a cespitose habit. It is recognized by its 3 styles, 1 stamen, trigonous achene, and oblong-lanceolate, conspicuously ribbed, recurved floral scales.



Ecological characteristics: Found along riverbanks and stream shores.

Phenology: Fruiting in summer.

Family: Cyperaceae

Synonyms: Cyperus aristatus Rothbøll, Cyperus inflexus Muhl.

Known Distribution in Maine: This rare plant has been documented from a total of 11 town in the following county: Hancock, Kennebec, Penobscot, Washington.

Reason(s) for rarity: Population is approaching northern edge of range.

Conservation considerations: Degradation to river shores could be detrimental to populations.