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

Sporobolus compositus (Poir.) Merr.
Rough Dropseed (composite dropseed)
Poaceae (Grass family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #10797)

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Distribution of Sporobolus compositus
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Sporobolus compositus var. compositus

Species Information

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Perennial, strongly tufted grass from fibrous roots; stems nearly or quite solid, longitudinally grooved, smooth, usually 60-100 cm tall.
Sheaths open, smooth or soft-hairy; blades usually in-rolled, tough, 1-4 mm wide, mostly soft-hairy above, especially near the ligules, the collars smooth or slightly hairy near the margins; ligules scarcely 0.5 mm long.
Inflorescence a narrow, spikelike panicle, up to 15 cm long, usually at least partially enclosed in the sheath, the branches erect; spikelets 1-flowered, strongly flattened; glumes blunt, the lower ones 2.5-3 mm long, the upper ones about 1 mm longer; lemmas blunt, smooth, 4-5 mm long, paleas nearly equal to the lemmas; lodicules fan-shaped, about 0.5 mm long; anthers 1.5-2.5 mm long.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Mesic to dry grasslands and shrublands in the steppe zone; rare in SC and SE BC; E to PQ, NB and NS and S to ME, MA, PA, NC, GA, AL, MS, LA, TX, NM, AZ, ID and WA.

Source: The Illustrated Flora of British Columbia


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.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References