Tridens flavus

Tall redtop or Purple-top is a 2 1/2-7 ft. tall perennial grass. In mass, this species puts a purple top on old fields and open woods. The plant becomes brown in fall. Fantastic nesting material for birds. Part-full sun and dry soils. Larval Host: Cross-line skipper, Broad-winged skipper, Little Glassywing skipper, Large Wood Nymph.