Hyperthelia dissoluta

HABIT Perennial; caespitose. Culms erect; 100–300 cm long; without nodal roots, or with prop roots. Leaf-sheath auricles absent, or erect. Ligule an eciliate membrane; 2–3(–24) mm long. Leaf-blades 15–30 cm long; 3–6 mm wide.

INFLORESCENCE Synflorescence compound; fastigiate. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 5–7 cm long; scarious; glabrous, or hirsute. Peduncle 3–5 cm long; glabrous, or pilose above.

Racemes 2; paired; erect; 2–3 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform. Rhachis internode tip oblique; flat. Raceme-bases filiform; unequal (the longer measured); 2–3 mm long; glabrous; extended into an oblong appendage (4–11 mm); with 4–11 mm long appendage.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 4 mm long; setose; tip oblique.

STERILE SPIKELETS Basal sterile spikelets well-developed; lower raceme 2 in number; 0 in upper raceme; male; lanceolate; 8–15 mm long; equalling fertile. Basal sterile spikelet lower glume muticous.

Companion sterile spikelets well-developed; male; lanceolate; 9–14 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet callus cuneate; 0.3–0.8 mm long; acute. Companion sterile spikelet glumes coriaceous; muticous, or awned; one glume awned; with 0–6 mm long awn. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 10–14 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 3–6 mm long; pilose; base pungent; attached obliquely. Spikelet callus hairs white.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; yellow; without keels; 10–14 -veined. Lower glume surface with a longitudinal median groove. Lower glume apex dentate; 2 -fid; setaceously attenuate. Upper glume oblong; coriaceous; without keels; 3 -veined. Upper glume apex emarginate; muticous, or mucronate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 5–6 mm long; hyaline; 2 -veined; ciliate on margins. Fertile lemma linear; 6 mm long; hyaline; without keel; 3 -veined. Lemma margins ciliate. Lemma apex dentate; 2 -fid; incised 0.1 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 50–100 mm long overall; with twisted column. Column of lemma awn hirtellous. Palea absent or minute.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. North America: Mexico. South America: Mesoamericana.

NOTES Andropogoneae. FTEA.

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