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Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Panicum congestum

HABIT Perennial; caespitose. Culms erect; 30–50 cm long. Culm-internodes unequal, the lower longer; distally hirsute. Culm-nodes brown; pubescent. Lateral branches ample; arising from upper culm. Leaf-sheaths hirsute. Ligule a ciliate membrane; 1 mm long. Collar pubescent. Leaf-blades linear, or lanceolate; 1.5–5 cm long; 2–4 mm wide. Leaf-blade surface hirsute; hairy on both sides. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; comprising 2–3(–9) fertile spikelets; embraced at base by subtending leaf. Peduncle 0.4 cm long.

Panicle contracted; linear; 2 cm long; bearing few spikelets. Panicle axis pilose. Panicle branches pilose.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels villous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2.8–3.2 mm long; 1 mm wide; falling entire. Rhachilla internodes elongated between glumes.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 2.2–2.6 mm long; 0.75 length of spikelet; membranous; without keels; 5–7 -veined. Lower glume surface pilose. Lower glume apex acute. Upper glume elliptic; 2.5 mm long; 0.9 length of spikelet; membranous; without keels; 9 -veined. Upper glume surface pilose. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 9 -veined; pilose; acute. Palea of lower sterile floret 0.66 length of lemma. Fertile lemma elliptic; dorsally compressed; 2.4 mm long; 0.8 mm wide; indurate; without keel; 5 -veined. Lemma surface papillose. Lemma margins involute. Lemma apex apiculate; pubescent. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp; ellipsoid; light brown. Embryo 0.33 length of caryopsis. Hilum elliptic.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Zuloaga 1994.

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