New York Natural Heritage Program
Green Parrot's-feather
Myriophyllum pinnatum (Walt.) B.S.P.
Myriophyllum pinnatum Troy Weldy
Family: Water-Milfoil Family (Haloragaceae)

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: G5
A Global Rarity Rank of G5 means: This species is demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.

Did you know?
This is one of only two species of Myriophyllum in the state that has both alternate and whorled leaves. The other one is Myriophyllum farwellii, also rare. It's common name comes from the feathery appearance of its leaves and the genus name means numberless (Myrio) leaves (phyllum) referring to the many divided leaves (Fernald 1970).

State Ranking Justification [-]
There are only four existing populations and one of these may have been extirpated from the incursion of seawater. There are seven historical populations from the first half of the 20th century in heavily developed areas and most of these are probably extirpated.

Short-term Trends [-]

Long-term Trends [-]