State and Global Rarity Ranks

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State Rarity Ranks

  • S1 Critically imperiled in Maine because of extreme rarity (five or fewer occurrences or very few remaining individuals or acres) or because some aspect of its biology makes it especially vulnerable to extirpation from the State of Maine.
  • S2 Imperiled in Maine because of rarity (6-20 occurrences or few remaining individuals or acres) or because of other factors making it vulnerable to further decline.
  • S3 Rare in Maine (20-100 occurrences).
  • S4 Apparently secure in Maine.
  • S5 Demonstrably secure in Maine.
  • SH Known historically from the state, not verified in the past 20 years.
  • SX Apparently extirpated from the state, loss of last known occurrence has been documented.
  • SU Under consideration for assigning rarity status; more information needed on threats or distribution.
  • S#? Current occurrence data suggests assigned rank, but lack of survey effort along with amount of potential habitat create uncertainty (e.g. S3?).

Note: State Rarity Ranks are determined by the Maine Natural Areas Program.

Global Rarity Ranks

  • G1 Critically imperiled globally because of extreme rarity (five or fewer occurrences or very few remaining individuals or acres) or because some aspect of its biology makes it especially vulnerable to extinction.
  • G2 Globally imperiled because of rarity (6-20 occurrences or few remaining individuals or acres) or because of other factors making it vulnerable to further decline.
  • G3 Globally rare (20-100 occurrences).
  • G4 Apparently secure globally.
  • G5 Demonstrably secure globally.
  • GNR Not yet ranked.

Note: Global Ranks are determined by NatureServe.

State Legal Status

  • E ENDANGERED; Rare and in danger of being lost from the state in the foreseeable future; or federally listed as Endangered.
  • T THREATENED; Rare and, with further decline, could become endangered; or federally listed as Threatened.

Note: State legal status is according to 5 M.R.S.A. 13076-13079, which mandates the Department of Conservation to produce and biennially update the official list of Maine's Endangered and Threatened plants. The list is derived by a technical advisory committee of botanists who use data in the Maine Natural Areas Program's database to recommend status changes to the Department of Conservation.

Non-Legal status

  • SC SPECIAL CONCERN; Rare in Maine, based on available information, but not sufficiently rare to be considered Threatened or Endangered.
  • PE Potentially Extirpated; Species has not been documented in Maine in past 20 years or loss of last known occurrence has been documented.