Eastern Gamagrass

Tripsacum dactyloides

Alternate names
Gamagrass

Weed Description
A perennial from large, thick rhizomes that may reach 6 feet in height. Eastern Gamagrass has a conspicuous spike seedhead that is jointed and is primarily a weed of pastures, hay fields, abandoned fields, roadsides, and along the edges of woods. This grass is found from Massachusetts south to Florida.

Leaves
Leaf blades may reach 2 feet in length and 1 inch in width, and are rough to the touch but mostly without hairs except those that occur at the base of the upper leaf surfaces. Leaves lack auricles but have a ligule that is a fringe of hairs, approximately 1 to 1 1/2 mm in length. Ligules may be fused at the base taking on the appearance of a ligule that is both membranous and a fringe of hairs.

Stems
Sheaths are without hairs and are split at least part way up the stem with overlapping margins. Stems may reach 6 feet or more in height.

Flowers
Seedheads (usually 1 to 3) are terminal spikes that are from 4 to 12 inches in length. Spikes consist of many tightly fused spikelets that eventually take on the appearance of being jointed.

Roots
Plants have very thick rootstocks, usually much larger than the width of the plant itself.

Identifying Characteristics
The large, thick rootstocks and relatively large leaves of this plant helps to distinguish it from almost any other grass. Additionally, the rather unique terminal seedhead is a good identifying characteristic of this species.

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University of Missouri

Eastern Gamagrass

Tripsacum dactyloides