Tripogon siamensis

HABIT Perennial; caespitose. Culms erect; 30–45 cm long. Ligule a ciliolate membrane. Leaf-blades filiform; convolute; 10–25 cm long; 2–3 mm wide. Leaf-blade surface scaberulous; rough adaxially. Leaf-blade apex acute.

INFLORESCENCE Inflorescence composed of racemes; shorter than basal leaves.

Racemes 1; single; erect; flexuous; unilateral; 10–25 cm long. Rhachis angular. Spikelet packing broadside to rhachis; lax; regular; 2 -rowed.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 8–10 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 7–11 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 4–5 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex with a unilateral tooth; acute. Upper glume lanceolate; 4–5 mm long; 1–1.1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea; persisting on inflorescence. Lemma of lower sterile floret similar to upper glume; elliptic; 4–5 mm long; membranous; 1 -veined; without lateral veins; acute; mucronate. Fertile lemma oblong; 4–4.5 mm long; membranous; without keel; 3 -veined. Lemma lateral veins extending close to apex. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; 3 mm long overall. Palea 0.5 length of lemma; 2 -veined. Palea keels winged; narrowly winged; ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 1 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-tropical: Indo-China.

NOTES Eragrostideae. Bor.

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