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.

Panicum laevinode

HABIT Annual; caespitose. Butt sheaths sparsely hairy. Culms erect; 15–60 cm long; compressible; 2–4 -noded. Culm-internodes distally glabrous, or pilose; with tubercle-based hairs. Culm-nodes brown; glabrous, or pubescent. Lateral branches lacking, or sparse. Leaf-sheaths glabrous on surface, or pilose; with tubercle-based hairs. Ligule a ciliolate membrane; 1–2 mm long. Leaf-blades 5–20 cm long; 2.5–6 mm wide; flaccid. Leaf-blade midrib prominent beneath. Leaf-blade surface glabrous, or pilose; sparsely hairy; with tubercle-based hairs. Leaf-blade apex acute, or acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 5–20 cm long. Primary panicle branches spreading; 1 -nate; branching divaricately. Panicle axis glabrous, or pilose; with tubercle-based hairs.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels 0.5–5 mm long; tip cupuliform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or ovate; dorsally compressed; acuminate; 2.4–3.5 mm long; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume oblate; clasping; 0.33 length of spikelet; membranous; pallid; without keels; 0–5 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex truncate, or obtuse. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 7–9 -veined. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 7–9 -veined; acuminate. Palea of lower sterile floret 0.75 length of lemma. Fertile lemma elliptic; dorsally compressed; 1.75–2 mm long; indurate; pallid, or light brown; shiny; without keel; 7 -veined. Lemma lateral veins prominent. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

FLOWER Anthers 3; 1 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; 1.5 mm long; pallid. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Fl NSW 1993.

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