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.

Trisetum spellenbergii

HABIT Perennial. Rhizomes short. Culms geniculately ascending; 40–60 cm long; 2–4 -noded. Culm-internodes distally glabrous. Leaf-sheaths loose; longer than adjacent culm internode. Ligule an eciliate membrane; 4.5–6 mm long; scaberulous on abaxial surface; lacerate. Leaf-blades 20–30 cm long; 2–3.5 mm wide; 10–20 cm long at summit of culm. Leaf-blade surface scabrous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; loose; 9–14 cm long; 2–8 cm wide. Primary panicle branches 2–5 -nate; whorled at most nodes; 3.5–5 cm long; bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising (4–)5–6 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 7–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5 mm long; pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 5.5–6.5 mm long; 0.8–0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein smooth, or scaberulous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 6.5–7.5 mm long; 1.1–1.5 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein smooth, or scaberulous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 4–6.5 mm long; membranous; shiny; keeled; 5 -veined. Lemma lateral veins prominent. Lemma apex dentate; 2 -fid; with lobes 2 mm long; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 8–12 mm long overall; with twisted column. Palea gaping; 3.5–5 mm long; hyaline. Palea keels scaberulous; ciliolate.

FLOWER Lodicules 2; 1–1.5 mm long; entire, or 2-toothed. Anthers 3; 1.2–2.5 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico.

NOTES Aveneae. Soreng 2005.

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