Agrostis gigantea Roth
redtop
Poaceae (Grass family)

Introduction to Vascular Plants

Photograph

© Jamie Fenneman     (Photo ID #7363)


Map

E-Flora BC Static Map

Distribution of Agrostis gigantea
Click here to view the full interactive map and legend

Species Information

General:
Perennial tufted grass from tough, underground, scaly rhizomes to 25 cm long; stems 20-120 cm tall.
Leaves:
Sheaths smooth; blades 4-10 cm long, 3-8 mm wide, usually flat; ligules longer than wide, 2-6 mm long.
Flowers:
Inflorescence open, broadly egg-shaped, 8-25 cm long, the branches spreading, the lower branches 4-7 cm long, but mixed with many short branches resulting in a crowding of the spikelets to the branch base (except in shade plants), the branches spreading broadly at flowering time and remaining so; glumes 1.7-3.2 mm long; lemmas 1.5-2.2 mm long, awnless or rarely with short, straight awns from near the tips; callus hairs sparse, up to 0.5 mm long; rachillas absent; paleas 0.7-1.4 mm long, as least 1/2 as long as the lemmas; anthers 1-1.4 mm long.
Notes:
This species was formerly combined with A. stolonifera under the illegitimate name A. alba. It is distinguished from A. stolonifera by its underground rhizomes, its open inflorescence and tolerance of much drier habitats.

SourceThe Illustrated Flora of British Columbia

Illustration

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Yellow
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
Source:  The USDA

Ecology

Ecological Framework for Agrostis gigantea

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Avg

Min

Max

Elevation (metres)
987 344 2147
Slope Gradient (%)
7 0 95

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

187 0 355
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 0 8
Modal Nutrient Regime
Class
C
# of field plots
 species was recorded in:
92
Modal BEC Zone Class
IDF

All BEC Zones (# of stations/zone) species was recorded in

ESSF(13), ICH(16), IDF(55), MS(1), PP(4), SBS(2)

Habitat and Range

Dry to mesic roadsides, fields and waste places in the lowland and montane zones; common throughout BC; introduced from Europe.

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Agrostis alba
Agrostis gigantea var. dispar (Michx.) Philipson
Agrostis nigra With.
Agrostis stolonifera subsp. gigantea (Roth) Schuebl. & Martens
Agrostis stolonifera var. major