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.

Trisetaria macrochaeta

HABIT Annual; culms solitary, or caespitose. Culms erect, or geniculately ascending; 10–22 cm long. Leaf-sheaths smooth, or scaberulous; glabrous on surface. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades flat, or convolute; 4–8 cm long; 1–1.5 mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface puberulous; hairy adaxially. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; oblong, or ovate; 1–7 cm long; 0.5–3.5 cm wide. Primary panicle branches 0.5–3 cm long. Panicle axis scabrous. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 3.5–4 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes glabrous, or pubescent.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume linear, or lanceolate; 2.5–3 mm long; 0.7–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex attenuate; muticous, or mucronate, or awned; 1 -awned. Lower glume awn 0.5 mm long. Upper glume ovate; 3.5–4 mm long; 1–1.25 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex entire, or dentate; 2 -fid; acuminate; muticous, or mucronate, or awned; 1 -awned. Upper glume awn 0.5 mm long.

FLORETS Fertile lemma lanceolate; 3 mm long; membranous; shiny; keeled; 3 -veined. Lemma surface glabrous, or pubescent. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.6 way up back of lemma; geniculate; 5–7 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 1.5 mm long; shorter than principal. Palea gaping; linear; 0.66 length of lemma; hyaline. Palea keels scabrous. Palea apex dentate; 2 -fid.

FLOWER Anthers 3; 1 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Europe: southwestern. Africa: north. Asia-temperate: western Asia.

NOTES Aveneae. Fl Afr N 1993.

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