Tridens hackelii

HABIT Perennial; caespitose. Butt sheaths thickened and forming a bulb; glossy. Culms 30–45 cm long; 1 -noded. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades conduplicate, or convolute; 10–15 cm long; 1–2 mm wide. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; comprising 25–35 fertile spikelets.

Panicle contracted; linear; 10–12 cm long. Primary panicle branches 2–3 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 6–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume oblong; 4 mm long; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 5–5.5 mm long; membranous; without keel; 3 -veined. Lemma midvein pubescent; hairy below. Lemma lateral veins excurrent. Lemma margins ciliate; hairy below. Lemma hairs 1 mm long. Lemma apex dentate; 3 -fid; mucronate. Palea lanceolate; bowed outwards. Palea keels scabrous. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 0.75 mm long; retained within floret.

FRUIT Caryopsis with adherent pericarp; lanceolate, or ellipsoid; plano-convex; 1.5–2 mm long. Embryo not projecting. Hilum punctiform.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Eragrostideae. Parodi 1993.

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