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.

Trisetaria vaccariana

HABIT Annual; culms solitary. Culms erect; 6–16 cm long; 3–4 -noded. Culm-internodes estriate; smooth; distally glabrous, or pubescent. Culm-nodes purple. Lateral branches lacking, or sparse. Leaf-sheaths without keel; pubescent; outer margin hairy. Ligule a ciliolate membrane; 1–1.5 mm long. Leaf-blades 3–6 cm long; 1–2 mm wide. Leaf-blade surface scabrous; rough adaxially; pubescent. Leaf-blade margins scabrous. Leaf-blade apex obtuse, or abruptly acute; callose.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; oblong; continuous; 2–3 cm long; 0.5–1 cm wide. Primary panicle branches 1–2 -nate. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong; scabrous.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose.

GLUMES Glumes persistent; similar; reaching apex of florets, or exceeding apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 4–5 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume surface glabrous, or pilose. Lower glume apex acuminate. Upper glume lanceolate; 4–5 mm long; 1–1.4 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface glabrous, or pilose. Upper glume apex acuminate.

FLORETS Fertile florets with the lowest dissimilar. Lowest fertile lemma glabrous. Fertile lemma lanceolate; 4 mm long; membranous; shiny; without keel; 5 -veined. Lemma midvein scabrous. Lemma surface villous. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.75 way up back of lemma; geniculate; 4 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 0.5 mm long; shorter than principal. Palea gaping; 1 mm long; hyaline. Palea keels scabrous. Rhachilla extension pilose.

FLOWER Lodicules 2; 0.4 mm long. Anthers 3; 1.7–2.3 mm long; purple. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Africa: north.

NOTES Aveneae. Fl Afr N 1997.

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