Achnatherum richardsonii (Link) Barkworth
spreading needlegrass (Richardson's needlegrass)
Poaceae (Grass family)

Introduction to Vascular Plants


© Bryan Kelly-McArthur     (Photo ID #87634)


E-Flora BC Static Map

Distribution of Achnatherum richardsonii
Click here to view the full interactive map and legend

Species Information

Perennial tufted grass from fibrous roots; stems 30-100 cm tall.
Sheaths smooth to slightly hairy; blades 0.8-3 mm wide; lower ligules 0.1-0.5 mm long, higher on the sides than on the back.
Inflorescence a panicle, 8-30 cm long, the branches zig-zag, broadly spreading, the mature spikelets drooping at the ends of the branches; glumes green, unequal, the lower ones 9-15 mm long, the upper 2-3 mm shorter than the lower; lemmas 4.5-5.5 mm long, smooth above, sparsely hairy below, the hairs 0.2-0.5 mm long, awned, the awns 15-25 mm long, twice bent, the first segments rough or short-hairy, the terminal segments zig-zag, persistent; paleas 1/2-3/5 as long as the lemmas, the calluses 0.4-0.7 mm long, blunt.

SourceThe Illustrated Flora of British Columbia


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.


Ecological Framework for Achnatherum richardsonii

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




Elevation (metres)
989 357 2030
Slope Gradient (%)
12 0 140

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

199 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 0 6
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

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

BG(26), BWBS(3), ESSF(10), IDF(374), MS(20), PP(65), SBPS(31), SBS(28)

Habitat and Range

Moist to dry slopes and open forests in the steppe and montane zones; locally frequent in SC, SE and WC BC; N to YT, E to MB and S to SD, CO, ID and WA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Stipa richardsonii Link