GrassBase - The Online World Grass Flora

Descriptions

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

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

Sorghum trichocladum

HABIT Perennial; caespitose. Culms 100–150 cm long. Culm-nodes bearded. Ligule an eciliate membrane. Leaf-blades 20–40 cm long; 3–8 mm wide.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; oblong; 10–15 cm long. Primary panicle branches simple; 2–4 cm long. Panicle branches capillary; flexuous.

Racemes 2–3 cm long; bearing few fertile spikelets; bearing 2–5 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip transverse.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; flattened; 4–5 mm long; villous; with dark brown hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; linear; dorsally compressed; 4–5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; pubescent; with white hairs; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base obtuse.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; much thinner above; dark brown; without keels; keel-less except near apex. Lower glume surface villous. Lower glume hairs dark brown; 1–3 mm long. Lower glume apex obtuse. Upper glume ovate; coriaceous; much thinner above; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline; 2 -veined; acute. Fertile lemma oblong; hyaline; 1 -veined. Lemma apex lobed; 2 -fid; incised 0.33 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15–25 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Lodicules 2; oblong; fleshy; ciliate. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Andropogoneae. Fl Nov Gal 1993.

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