New York Natural Heritage Program
Tidal Spikerush
Eleocharis aestuum Hines & A. Haines
Eleocharis aestuum plants 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: G3
A Global Rarity Rank of G3 means: This species is either rare and local throughout its range (21 to 100 occurrences), or found locally (even abundantly at some of its locations) in a restricted range (e.g. a single physiographic region), or is vulnerable to extinction throughout its range because of other factors.

Did you know?
The species was noted as different from the closely related species Eleocharis diandra and Eleocharis ovata in 1975 but it was not formally assigned its present scientific name until the year 2000. It was referred to for many years by the unpublished name Eleocharis pallidostachys. It is globally rare because the only recent records are from the Androscoggin and Kennebec rivers in Maine and the Hudson River in New York. Its species name aestuum means "tidal" since it is found in the freshwater tidal areas of these three rivers.

State Ranking Justification [-]
There are two existing populations, one large and one small. There are 10 historical populations from the Hudson River area, mostly from the 1930s when intensive surveys were done.

Short-term Trends [-]

Long-term Trends [-]