New York Natural Heritage Program
Cypress-knee Sedge
Carex decomposita Muhl.
Carex decomposita line drawing Britton, N.L., and A. Brown (1913); downloaded from USDA-Plants Database.
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: SH
A State Rarity Rank of SH means: This plant is only historically known from New York State, typically with the last plant observed over 20 years ago. Many SH plants have not been seen in 50-100 years.

Global Rarity Rank: G3G4
A Global Rarity Rank of G3G4 means: Vulnerable globally, or Apparently Secure -- At moderate risk of extinction, with relatively few populations or locations in the world, few individuals, and/or restricted range; or uncommon but not rare globally; may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign a single conservation status.

Did you know?
This species is rare and local throughout its range and very rare in the north but Carex decomposita appears to prefer the most inhospitably thick buttonbush swamps. Therefore, perhaps it is more common than believed but simply difficult for people to penetrate the habitat it prefers.

The specific epithet decomposita means decompound in reference to the much compound inflorescences (Fernald 1970).

State Ranking Justification [-]
There are no known populations of this plant in New York, but at least six historical locations have been recorded. These sites are either on floating logs or within difficult to survey buttonbush swamps. There is a high likelihood that this is hiding out somewhere within New York, but it is probably a very local and very rare plant within the state. More survey effort is needed in an attempt to relocate this plant.

Short-term Trends [-]

Long-term Trends [-]