purpletop

Family

Poaceae

Scientific Name

Tridens flavus

Habit

A perennial with short, thick rhizomes that is most noticeable from August through October when these plants reach 4 or 5 feet in height and produce dark purple panicles

Leaves

Leaves are somewhat flattened and appear folded in the sheath and have a relatively prominent white midvein. Leaves are 8 to 17 mm wide, usually hairy except near the bases, lacking auricles, and with a ligule that is a fringe of hairs less than 1 mm in length. Sheaths are round and usually hairy only near the top.

Identifying Characteristics

Additionally, the short, thick rhizomes and purple seed head are characteristics that help in the identification of this weed.

Flower Seed Head

The seedhead is an open panicle that is dark purple in color. Individual spikelets are 6 to 8 mm long, 1 to 2 mm wide, and purple in color.

Seed Fruit

Seed length is 1.8 -2mm.

Where Found

Purpletop is primarily a weed of hay fields, pastures, abandoned fields, and roadsides that is found from New Hampshire south to Florida. It prefers full sun, and moist dry conditions.