New York Natural Heritage Program
Southern Twayblade
Neottia bifolia (Raf.) Baumbach
Monocots
Listera australis Tagliapietra- Cherbavaz
Family: Orchid Family (Orchidaceae)

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: S1S2
A State Rarity Rank of S1S2 means: Critically Imperiled or Imperiled in New York - Especially or very vulnerable to disappearing from New York due to rarity or other factors; typically 20 or fewer populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines. More information is needed to assign a single conservation status.

Global Rarity Rank: G4
A Global Rarity Rank of G4 means: This species is apparently secure globally (typically with more than 100+ populations), though it may be quite rare in parts of its range, especially at the periphery.


Did you know?
There are four species of Listera in New York and all of them are rare except Listera cordata, the heartleaf twayblade. These orchids are often very hard to see and great care must be taken when searching for them to avoid trampling. The small aboveground stem may not appear every year and when it does it only lasts for a few weeks. The genus name is dedicated to Martin Lister, 1638-1711, a famous English naturalist.

State Ranking Justification [-]
There are seven known populations but half of these are relatively small. One large site contains approximately 2000 plants. There are roughly 20 historical populations that should be surveyed. There are undoubtedly more populations still to find.

Short-term Trends [-]

Long-term Trends [-]