Cathestecum

J. Presl
Treatment appears in FNA Volume 25. Treatment on page 272.

Plants annual or perennial; monoecious or dioecious; often stoloniferous. Culms 5-40 cm, sometimes decumbent. Leaves mostly basal; sheaths open; ligules of hairs; blades 0.5-2 mm wide. Inflorescences terminal, racemelike panicles of short branches, usually exceeding the upper leaves, sometimes appearing 1-sided; branches about 0.5 cm, not appressed to the rachises, with 3 spikelets, bases strongly curved, shortly strigose, axes not extending beyond the distal spikelets; disarticulation at the base of the branches. Spikelets pedicellate or sessile, lateral spikelets with shorter pedicels than the central spikelet or sessile; lateral spikelets with 2 florets, lower florets usually staminate or sterile, rarely pistillate, upper florets much reduced, usually sterile; central spikelets pedicellate, with 3 florets, lowest florets bisexual or pistillate (staminate in staminate plants), distal florets staminate or sterile. Glumes 2, very unequal, shorter than the spikelets, unawned; lower glumes shorter than the upper glumes, those of the central spikelets flabellate, glabrous, veinless; upper glumes approximately equal to the adjacent lemmas, 1-veined, acuminate; lemmas thinner than the glumes, pilose, 3-veined, 4-lobed, all 3 veins excurrent, forming awns that equal or exceed the lobes, lobes of the sterile florets usually deeper than those of the other florets; paleas 2-veined, veins often extending as awns, x = 10.

Discussion

Cathestecum is a genus of six species that extends from the southern United States to Guatemala; two are native to the Flora region. Columbus (1999) advocated including Cathestecum in Bouteloua, but the traditional treatment is adopted here.

Key

1 Stolon internodes to 12 cm long, straight or almost so; culms 5-15 cm tall; spikelets frequently reddish or purplish; lateral spikelets of branches with bisexual florets poorly-developed, sterile (rarely staminate) florets; central spikelet on staminate branches with sparsely pilose lemmas Cathestecum brevifolium
1 Stolon internodes usually 15 cm or longer, strongly arching; culms 10-30 cm tall; spikelets frequently pale green; lateral spikelets of branches with bisexual florets usually well-developed, usually staminate or sterile; central spikelet on staminate branches with glabrous lemmas Cathestecum erectum