FEDERAL STATUS
1. US Fish and Wildlife Service (Notice of Review 1996)
E: Endangered: taxa formally listed as endangered (one plant species listed in Alaska).
T: Threatened: taxa formally listed as threatened (no plant taxa listed in Alaska).
P: Proposed E or T: taxa formally proposed for listing as endangered or threatened (no plant taxa proposed in Alaska).
C: Candidate: taxa for which the Service has on file sufficient information on biological vulnerability and threat to support proposals to list as endangered or threatened (no Candidate plant taxa in Alaska).
Note: The US Fish and Wildlife Service has discontinued the designation of Category 2 candidates.
2. US Forest Service
S: Sensitive: taxa identified by the Regional Forester for which population viability is a concern as evidenced by significant current or predicted downward trends in populations or habitat.
INTERNATIONAL STATUS
1. Arctic Environmental Protection Strategy (AEPS).
CAFF: taxa identified as rare by the Conservation of Arctic Flora and Fauna program. These are taxa whose main distribution is in the Arctic (as defined by Yurtsev 1994) and that are generally known from fewer than 20 locations world-wide (equivalent to a Heritage Program Global Rank of G1 - G2).
GLOBAL RANK (Global ranks are based on the world-wide status of a taxon and are assigned by The Nature Conservancy and an international network of Natural Heritage Programs and Conservation Data Centers.
G1: Critically imperiled globally because of extreme rarity (5 or fewer occurrences, or very few remaining individuals), or because of some factor of its biology making it especially vulnerable to extinction. (Critically endangered throughout its range.)
G2: Imperiled globally because of rarity (6 to 20 occurrences) or because of other factors demonstrably making it very vulnerable to extinction throughout its range. (Endangered throughout its range.)
G3: Either very rare and local throughout its range or found locally (even abundantly at some of its locations) in a restricted range (21 to 100 occurrences). (Threatened throughout its range.)
G4: Widespread and apparently secure globally, though it may be quite rare in parts of its range, especially at the periphery.
G5: Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
T#: Global rank of the described subspecies or variety.
G#G#: Global rank of species uncertain, best described as a range between the two ranks.
G#Q: Indicates some uncertainty about taxonomic status that might affect global rank.
STATE RANK (State ranks are based on the status of the taxon within a particular state or province. The state ranks for taxa presented in this guide often differ from the ranks for the same taxa in other states or provinces.)
S1: Critically imperiled in state because of extreme rarity (5 or fewer occurrences, or very few remaining individuals), or because of some factor of its biology making it especially vulnerable to extinction. (Critically endangered throughout in state.)
S2: Imperiled in state because of rarity (6-20 occurrences), or because of other factors making it very vulnerable to extirpation from the state .
S3: Rare or uncommon in the state (21-100 occurrences).
SP: Occurring in nearby state or province; not yet reported in state, but probably will be encountered with further inventory.
S#S#: State rank of species uncertain, best described as a range between the two ranks.