|
State Rank |
Definition
|
|
S1 |
Critically
imperiled because of extreme rarity or because of some
factor (s) of its biology making it especially
vulnerable to extinction. |
|
S2 |
Imperiled
because of rarity or because of other factors
demonstrably making it very vulnerable to extinction
throughout its range. |
|
S3 |
Either very rare and
local throughout its range, or found locally (even
abundantly at some of its locations) in a restricted
range, or vulnerable to extinction throughout its range
because of other factors. |
|
S4 |
Apparently secure,
though it may be quite rare in parts of its range,
especially at the periphery. |
|
S5 |
Demonstrably secure,
though it may be quite rare in parts of its range,
especially at the periphery. |
|
SU |
Possibly in peril, but
status uncertain; more information needed. |
|
SH |
Historically known;
may be rediscovered. |
|
SX |
Believed to be
extinct; historical records only. |
|
S# |
Indicates a range of uncertainty about the
rarity of the species. |