UMass Extension Landscape, Nursery and Urban Forestry Program

Tridens flavus

Common Name: 
purpletop, greasegrass, tall redtop
Scientific Name: 
Tridens flavus (L.) A.S. Hitchc., Triodia flava, Triodia flavus
Family Name: 
Poaceae (Graminae) - Grass Family
Identification Notes
Life Cycle: 
introduced perennial, reproducing by seed and short thick, rhizomes
Culms: 
upright, smooth, round but flattened below, tuft forming
Culms of Purpletop
Culms of Purpletop
Leaves: 
blades flat, long, tapering to narrow point, smooth, white midrib prominent, rough margins, distinct line perpendicular to midrib on underside, underside glossy, rolled in bud; auricles absent; ligule ring of hairs, very short; sheaths flattened or keeled
Leaves of Purpletop
Leaves of Purpletop
Seedheads: 
panicle, terminal, open, often drooping when mature, oval to pyramidal, purple to dark purple sometimes almost black, usually covered with an oily or grease-like substance
Seedheads of Purpletop
Seedheads of Purpletop
Seedheads of Purpletop