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.

Panicum decompositum

HABIT Perennial; caespitose; clumped densely. Rootstock evident. Culms 30–80 cm long; compressible; 3–4 -noded. Culm-nodes glabrous, or pubescent. Leaf-sheaths longer than adjacent culm internode; keeled; glabrous on surface, or pilose; with tubercle-based hairs. Ligule a ciliolate membrane; 2 mm long. Leaf-blades flat, or conduplicate, or involute; 25–50 cm long; 3–9.5 mm wide; glaucous. Leaf-blade midrib conspicuous. Leaf-blade surface glabrous, or pilose; with tubercle-based hairs. Leaf-blade margins scaberulous. Leaf-blade apex acute, or attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 15–30 cm long; with spikelets clustered towards branch tips. Primary panicle branches spreading; whorled at lower nodes. Panicle branches stiff; flat (at base); scabrous.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels 1–4 mm long; tip cupuliform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or ovate; dorsally compressed; compressed slightly; acuminate; 2.75–3.5 mm long; 1.25 mm wide; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.25–0.33 length of spikelet; membranous; without keels; 0–1 -veined. Lower glume lateral veins absent. Lower glume apex truncate, or obtuse. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 7 -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 -veined; acuminate. Palea of lower sterile floret 0.66–0.9 length of lemma. Fertile lemma elliptic, or oblong; dorsally compressed; 2–2.2 mm long; indurate; yellow, or dark brown; shiny; without keel; 7 -veined. Lemma lateral veins prominent. Lemma margins involute. Lemma apex obtuse. Palea involute; indurate.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid, or ovoid; 1.5 mm long. Embryo 0.5 length of caryopsis.

DISTRIBUTION Asia-temperate: eastern Asia. Australasia: Australia. Pacific: southwestern.

NOTES Paniceae. Fl NSW 1993.

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