Trichophorum pumilum (Vahl) Schinz & Thellung
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TAXONOMY
 
Family: Cyperaceae
Genus: Trichophorum
 
Species Synonyms: Trichophorum pumilum var. rollandii (Fern.) Hultén
Trichophorum pumilum ssp. rollandii (Fern.) Taylor & MacBryde
Trichophorum rollandii (Fern.) Hultén
Scirpus pumilus Vahl
Scirpus pumilus var. rollandii (Fern.) Beetle
Scirpus pumilus ssp. rollandii (Fern.) Raymond
Baeothryon pumilum (Vahl) A. &D. Löve
Scirpus rollandii Fern.
Common Names: dwarf bulrush
Rolland’s bulrush
 
DISTRIBUTION
 
Canada: Yukon Territory – southwestern Mackenzie District –northeastern British Columbia, southwestern and central Alberta – central Saskatchewan, eastern Quebec
Saskatchewan: central Saskatchewan; Saskatoon
Ecoregion: Moist Mixed Grassland
 
HABITAT
 
Saskatchewan: calcareous ground-water, bog-like fens
Associated Species: bristly muhly, golden sedge, lobelia, seaside arrowgrass, silvery primrose
 
RARITY STATUS
 
Provincial Status According
to Harms (2003):
Threatened
Nature Conservancy Status:
G5T3 N2T2 S1
Saskatchewan Species at
Risk Status:
None
COSEWIC Status:
None
 
Dwarf bulrush is threatened in Saskatchewan because it is rare and highly regionally restricted in the province. Most local populations are small.
 
SPECIES DESCRIPTION
 
Height: 5 – 14 cm
Roots: rhizome long, slender
Stems: loosely tufted, dead leaves at base, round, slender, smooth, grooved
Leaves: basal sheaths brown, persistent; leaves basal or nearly so, 2 – 8.5 mm long, much shorter than stems, ~ 0.5 mm wide
Inflorescence: spikelet solitary, terminal; bracts 1, shorter than spikelet, tip with a sharp, abrupt point
Spikelets: 3 – 6-flowered; 3 – 4.5 mm long; scales obtuse, brown
Flowers: perianth bristles absent; stamens 3; styles 3-cleft
Fruits: 1 – 2 mm long, egg-shaped, three-angled, smooth, scarcely beaked
 
TRICHOPHORUM KEY FOR SPECIES FOUND IN SASKATCHEWAN
 
1 Stems round, smooth
2
1 Stems three-angled, rough
3
   
2 Plants loosely tufted; inflorescence bracts with a sharp, abrupt point; perianth bristles absent
T. pumilum
2 Plants densely tufted; inflorescence bracts awned; perianth bristles 6
T. cespitosum
   
3 Flowers more than 15 per spike; perianth bristles white and silky, many times longer than achene
T. alpinum
3 Flowers less than 10 per spike; perianth bristles brown to white, shorter than achene
T. clintonii