BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Arctagrostis latifolia | Polargrass 



GENERAL BOTANICAL CHARACTERISTICS : 
Polargrass is a perennial, native, sod-forming grass.  Culms range from
1 to 4 feet (0.3-1.2 m) tall.  Leaf blades are 1.6 to 11.8 inches (4-30
cm) long and 0.16 to 0.56 inch (4-14 mm) wide.  Plants have a narrow,
somewhat open panicle that is 2.8 to 11 inches (7-28 cm) long.  There is
one flower per spikelet, and spikelets range from 0.12 to 0.18 inch
(3-4.6 mm) long.  The species is variable, but the typical form seldom
exceeds 1.8 feet (0.5 m) in height and has purple spikelets 4 mm long or
longer [10].


RAUNKIAER LIFE FORM : 
   Geophyte


REGENERATION PROCESSES : 
Polargrass reproduces both sexually and vegetatively.  Tillers spread
slowly, arising from rhizomes and forming dense clumps [18].  Seeds are
produced in all but the most northern latitudes [5].


SITE CHARACTERISTICS : 
Polargrass grows in wet meadows, along rivers, on tundra, in freshwater
marshes, and in inland levees [9,10,21,24].  It is best adapted to cold,
boggy soils and mesic upland soils [18].  In freshwater marshes
polargrass is more apparent on hummocks than in depressions [9].  The
inland levees are sandy and well-drained, and have a neutral pH.
Bluejoint-reedgrass (Calamagrostis canadensis) dominates in acidic, less
well-drained areas [21].  Along the Tanana River in Alaska, polargrass
stands are always underlain by permafrost with shallow active layers,
commonly 127 to 152 inches (50 to 60 cm) thick [24].

Common overstory dominants include Sitka alder (Alnus sitchensis), white
spruce (Picea glauca), black spruce (P. mariana), paper birch (Betula
papyrifera), and dwarf alpine birch (B. nana).  Understory associates
include Labrador tea (Ledum groenlandicum), mountain cranberry
(Vaccinium vitis-idaea), flowering dogwood (Cornus canadensis),
horsetail (Equisetum arvense), northern comandra (Geocaulon lividum),
bluejoint-reedgrass, rough fescue (Festuca altaica), tall fescue (F.
arundinacea), and crowberry (Empetrum nigrum).


SUCCESSIONAL STATUS : 
Facultative Seral Species

Polargrass codominates with other species in grassland tundra
communities.  Evidence suggests that it occurs in the early stages of
succession following fire [2].  In succession on river floodplains,
however, it is abundant only in late successional mixed white and black
spruce stands [24].


SEASONAL DEVELOPMENT : 
In the Matanuska Valley of Alaska, new panicles of polargrass appear
between mid and late June.  Anthesis is relatively inconspicuous,
occurring from early July to past the middle of the month.  Seed is
mature between September 15 and 25 [13].

Related categories for Species: Arctagrostis latifolia | Polargrass