Trisetum youngii

HABIT Perennial; caespitose. Culms erect; 30–90 cm long. Culm-internodes distally glabrous, or pilose. Leaves mostly basal. Leaf-sheaths glabrous on surface, or pilose. Ligule an eciliate membrane; lacerate; truncate. Leaf-blades 1–3 mm wide. Leaf-blade surface smooth; pilose.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear, or lanceolate; 5–20 cm long. Primary panicle branches appressed. Panicle axis pilose. Panicle branches pilose.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume elliptic; 0.75–1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume elliptic; 0.75 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 3.5 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface asperulous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.66 way up back of lemma; curved; 3–4 mm long overall. Palea gaping; hyaline.

FLOWER Anthers 3. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Australasia: New Zealand.

NOTES Aveneae. Cheeseman 1995.

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