Themeda quadrivalvis
Plants annual. Culms to 2 m, glabrous. Sheaths glabrous, flattened at the base; ligules 1-2.5 mm; blades to 60 cm long, 1-6 mm wide, usually folded. False panicles to 130 cm; sheaths subtending the rame clusters 17-50 mm, distal sheaths shorter and more strongly keeled, margins tuberculate; rames 1-3 per cluster, 8-10 mm, with 1-2 heterogamous spikelet pairs. Homogamous spikelets 4-7 mm; lower glumes many-veined, hairy distally, hairs papillose-based; upper glumes subequal to the lower glumes, 3-veined. Sessile heterogamous spikelets 4-6 mm; calluses 0.5-3 mm; lower glumes glabrous or sparsely hirsute; upper glumes 4.5-5.5 mm; awns 4-5 cm; pedicellate spikelets 4.5-5.5 mm, sterile. 2n = 18.
Distribution
Kans., Fla., Calif., La.
Discussion
A native of Malaysia, Themeda quadrivalvis has been found at scattered locations in the contiguous United States. Towne and Ballard (2002) reported that it is a common contaminant of the thistle seed sold for bird feeders. Most of the seeds are sterile, but a few are not. It is established in St. Landry and Iberia parishes, Louisiana, in addition to having escaped from cultivation in Florida (Baird and Thieret 1985)
Selected References
Lower Taxa
"decumbent" is not a number.