E-Flora BC: Electronic Atlas of the Flora of British Columbia

Agrostis gigantea Roth
redtop
Poaceae (Grass family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #7363)

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Distribution of Agrostis gigantea
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Species Information

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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.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

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

Habitat / Range

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

Source: The Illustrated Flora of British Columbia

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

Minimum

Average

Maximum

Elevation (metres) 344 987 2147
Slope Gradient (%) 0 7 95
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 187 355
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 4 8
Modal Nutrient Regime
Class
C
Number 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)

Climate

The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

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

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

General References