Cyperus houghtonii Torr.
Habitat: Light, usually dry, sandy soil, often with Pinus banksiana.
Range: Quebec to Manitoba, locally south to Massachusetts, Long Island, Virginia, Indiana, and Iowa.
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 houghtonii resembles Cyperus schweinitzii but with culms obtusely (versus sharply) angled and smooth (versus scabrous).
Phenology: Flowers July to October.
Synonyms: None noted.
Known Distribution in Maine: This rare plant has been documented from a total of 1 town(s) in the following county(ies): Kennebec. There is a single documented occurrence of Cyperus houghtonii in Maine. A specimen was collected by R.C. Bean with the New England Botanical Club in 1905 from the Sebasticook River.