Trisetum bulbosum

HABIT Perennial; caespitose. Butt sheaths thickened and forming a bulb. Culms erect; 30–50 cm long. Culm-internodes distally glabrous. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 1–2 mm long; lacerate; obtuse. Leaf-blades flat, or conduplicate, or involute; 2–5 cm long; 0.5–1.5 mm wide. Leaf-blade surface scaberulous; glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 8–10 cm long. Primary panicle branches appressed. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 6–7 mm long; 0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume elliptic; 7–8 mm long; 0.75 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 10 mm long; cartilaginous; keeled; 3 -veined. Lemma surface asperulous; rough below. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 12–15 mm long overall; with twisted column. Palea gaping; 0.5 mm long. Palea keels ciliolate.

FLOWER Anthers 3; 2 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex. Hilum linear.

DISTRIBUTION South America: southern South America.

NOTES Aveneae. Hitchc 1995.

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