Helictotrichon scabrivalve

HABIT Perennial. Rhizomes elongated. Butt sheaths thickened and forming a bulb. Culms erect; 40–100 cm long. Ligule an eciliate membrane; 6–12 mm long; lacerate. Leaf-blades 2–5 mm wide. Leaf-blade surface smooth, or scabrous.

INFLORESCENCE Inflorescence a panicle; embraced at base by subtending leaf.

Panicle open; lanceolate; 10–25 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 14–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; pilose. Floret callus pubescent; disarticulating obliquely.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 3–5 mm long; 0.75 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume lanceolate; 4–7 mm long; 0.5–1 length of adjacent fertile lemma; membranous; 1-keeled; 5–7 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 7 mm long; cartilaginous; without keel; 7–9 -veined. Lemma surface pubescent. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 13–15 mm long overall; with twisted column. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 2–2.7 mm long; eventually exserted, or retained within floret. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.5–3.5 mm long; hairy at apex. Hilum linear.

CLEISTOGENES AND VIVIPARY Cleistogenes absent, or present; in upper sheaths, or in lower sheaths.

DISTRIBUTION South America: western South America and southern South America.

NOTES Aveneae. Fl Pat 1995.

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