GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Tripsacum latifolium

HABIT Perennial. Rhizomes short. Culms geniculately ascending; robust; 250–500 cm long; 5–10 mm diam. Leaf-sheaths glabrous on surface, or pubescent. Leaf-sheath oral hairs lacking, or pubescent. Ligule a ciliolate membrane; 3 mm long. Leaf-blades 30–90 cm long; 40–70 mm wide. Leaf-blade surface pubescent; sparsely hairy; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Inflorescence composed of racemes; terminal and axillary.

Racemes 1(–3); single; ascending; straight; smoothly terete; unilateral; 10–30 cm long. Rhachis (female) fragile at the nodes; subcylindrical and excavated; 2.5–3 mm wide. Spikelet packing abaxial. Rhachis internodes oblong; 5–7 mm long; adherent to upper glume of sessile spikelet. Rhachis internode tip transverse; crateriform.

Sexes segregated; on bisexual branches; with male above. Spikelets sunken; solitary. Fertile spikelets sessile. Male spikelets sessile; 2 in a cluster.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 3–4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; reaching apex of florets; firmer than fertile lemma; shiny. Lower glume ovate; 1 length of spikelet; indurate; without keels. Lower glume apex acute. Upper glume ovate; cartilaginous; without keels. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile florets female. Fertile lemma oblong; hyaline; without keel. Palea hyaline.

MALE Male spikelets distinct from female; all deciduous together; 3–5 mm long; hairy; obtuse. Male spikelet glumes 2; coriaceous; muticous.

DISTRIBUTION North America: Mexico. South America: Mesoamericana and Caribbean.

NOTES Andropogoneae. Fl Meso-Am 1995.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.