Tridens flavus cupreus, commonly known as Purpletop, is a native warm-season bunchgrass found in prairies, open fields, roadsides, and woodland edges throughout Illinois. It prefers full sun and well-drained to moderately moist soils and is well-adapted to disturbed or open areas.
This tall, graceful grass is named for its striking purplish flower and seed heads, which appear in late summer to early fall and give a smoky-purple haze to the upper portion of the plant. The seed heads are slightly sticky or oily to the touch—hence the nickname "grease grass." Purpletop typically grows 3 to 5 feet tall, with upright, arching stems and fine-textured foliage that turns golden-tan in fall.
For Illinois native plant enthusiasts, Tridens flavus is a valuable addition to prairie restorations, native grass gardens, and erosion control plantings. It provides excellent cover and nesting material for wildlife and supports various insects, including grass-feeding caterpillars. Its distinctive purple seed heads add ornamental appeal and texture to late-season landscapes, especially when paired with Goldenrods, Asters, and other fall-blooming natives.
Tridens flavus cupreus, commonly known as Purpletop, is a native warm-season bunchgrass found in prairies, open fields, roadsides, and woodland edges throughout Illinois. It prefers full sun and well-drained to moderately moist soils and is well-adapted to disturbed or open areas.
This tall, graceful grass is named for its striking purplish flower and seed heads, which appear in late summer to early fall and give a smoky-purple haze to the upper portion of the plant. The seed heads are slightly sticky or oily to the touch—hence the nickname "grease grass." Purpletop typically grows 3 to 5 feet tall, with upright, arching stems and fine-textured foliage that turns golden-tan in fall.
For Illinois native plant enthusiasts, Tridens flavus is a valuable addition to prairie restorations, native grass gardens, and erosion control plantings. It provides excellent cover and nesting material for wildlife and supports various insects, including grass-feeding caterpillars. Its distinctive purple seed heads add ornamental appeal and texture to late-season landscapes, especially when paired with Goldenrods, Asters, and other fall-blooming natives.
Bloom: mid-summer to early fall
Habitats: areas along railroads; fields; limestone glades; meadows in wooded areas; powerline clearances in wooded areas; roadsides; savannas; woodland borders; woodland openings
Lifespan: perennial
Moisture: moist to dry-mesic
Plant type (height): grass (3 to 5 feet)
Requirements: full sun to partial sun
Soil: clay-loam; loam
