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

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

Introduction to Vascular Plants

© Bryan Kelly-McArthur  Email the photographer   (Photo ID #87634)

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Distribution of Achnatherum richardsonii
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Species Information

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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.

Source: The Illustrated Flora of British Columbia

Habitat / 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.

Source: The Illustrated Flora of British Columbia


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) 357 989 2030
Slope Gradient (%) 0 12 140
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 199 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 3 6
Modal Nutrient Regime
Number 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)


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 montane boreal & cool temperate.

Synonyms and Alternate Names

Stipa richardsonii Link

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References