New York Natural Heritage Program
Retrorse Flatsedge
Cyperus retrorsus var. retrorsus
Stephen M. Young
Family: Sedge Family (Cyperaceae)

State Protection: Endangered
listed species are those with: 1) 5 or fewer extant sites, or 2) fewer than 1,000 individuals, or 3) restricted to fewer than 4 U.S.G.S. 7 minute topographical maps, or 4) species listed as endangered by U.S. Department of Interior.

Federal Protection: Not Listed

State Rarity Rank: S1
A State Rarity Rank of S1 means: This plant is endangered/critically imperiled in New York because of extreme rarity (typically 5 or fewer populations or very few remaining individuals) or is extremely vulnerable to extirpation from New York due to biological factors.

Global Rarity Rank: G5T5
A Global Rarity Rank of G5T5 means: Secure globally - Both the species as a whole and the subspecies/variety are common in the world; widespread and abundant (but may be rare in some parts of its range).

Did you know?
The species name means "turned backward or downward" and refers to the perigynia of the spikelets that face downward when mature (Fernald 1950). A collection on Jones Beach Island in 2003 was the first time it had been seen on the island since 1935.

State Ranking Justification [-]
There are three existing populations but there is no information on population size from any one of them. There are three additional populations known, from 1899, the 1930s, and 1976 that have not been resurveyed although habitat still exists. There are eight populations that are extirpated due to loss of habitat.

Short-term Trends [-]

Long-term Trends [-]