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.

Rytidosperma virescens

HABIT Perennial; caespitose. Culms 40–55 cm long; 2–3 -noded. Leaf-sheaths pilose; outer margin hairy. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs; 1.2–1.5 mm long. Leaf-blades curved; filiform; 6–25 cm long; 1–2 mm wide; coriaceous; stiff. Leaf-blade surface scabrous; rough adaxially. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle; comprising 12–16 fertile spikelets.

Panicle open; linear; 4.5–7 cm long; bearing few spikelets. Primary panicle branches 2–4 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous; ciliate; hairy below.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 15–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.7–1.5 mm long. Floret callus evident; pilose. Floret callus hairs 1–2.5 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 16–19 mm long; 1 length of upper glume; membranous; without keels; 5–9 -veined. Lower glume lateral veins with cross-veins. Lower glume apex acute. Upper glume lanceolate; 16–19 mm long; 1.4 length of adjacent fertile lemma; membranous; without keels; 5–9 -veined. Upper glume lateral veins with cross-veins. Upper glume apex acute.

FLORETS Fertile lemma oblong; 12–16 mm long; chartaceous; without keel; 9 -veined. Lemma surface glabrous; with 2 transverse rows of hair tufts. Lemma hairs 5–7 mm long. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 10–17 mm long overall; with twisted column. Column of lemma awn 4–5 mm long. Lateral lemma awns arising on apex of lobes; 4–7 mm long. Palea 5–7 mm long; chartaceous. Palea keels ciliolate. Palea surface pilose; hairy on flanks. Palea apex dentate; 3 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; fleshy; ciliate. Anthers 3; 1.2–2 mm long.

FRUIT Caryopsis with adherent pericarp; 2–2.5 mm long.

DISTRIBUTION South America: southern South America.

NOTES Arundineae. Fl Pat 1993.

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