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 longiglume

HABIT Perennial; caespitose. Culms 10–30 cm long. Leaf-sheaths longer than adjacent culm internode; smooth, or scaberulous. Ligule a ciliolate membrane; 0.8–2 mm long; lacerate. Leaf-blades 4–7 cm long; 1–1.5 mm wide. Leaf-blade surface scabrous; rough adaxially. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; 4–5 cm long; 1.5–2.5 cm wide. Panicle axis glabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels smooth, or scaberulous.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 8–11 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5–2 mm long; pilose; with 2–3.5 mm long hairs. Floret callus pilose. Floret callus hairs 2–3.5 mm long; 0.33–0.5 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 8–11 mm long; 1 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume lanceolate; 8–11 mm long; 1.2–1.3 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 6–9 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface scabrous. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 8–11 mm long overall; with twisted column. Lateral lemma awns 0.5–1 mm long. Palea gaping; hyaline. Palea keels scaberulous. Palea apex with excurrent keel veins.

FLOWER Lodicules 2; 0.8 mm long. Anthers 3. Ovary glabrous, or pubescent on apex.

FRUIT Caryopsis with adherent pericarp; fusiform; 2.5 mm long; hairy at apex. Hilum punctiform. Endosperm farinose.

DISTRIBUTION South America: southern South America.

NOTES Aveneae. Fl Pat 1995.

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