Ischaemum pubescens

HABIT Perennial. Culms erect, or geniculately ascending; 70–100 cm long. Culm-internodes distally pruinose. Culm-nodes bearded. Leaf-sheaths loose; glabrous on surface, or pilose. Leaf-sheath auricles erect; 2–3 mm long. Ligule an eciliate membrane; 2–3 mm long; brown. Leaf-blades 10–18 cm long; 6–12 mm wide. Leaf-blade surface pilose; hairy on both sides. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; appressed back to back; 6–10 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes oblong; 4 mm long; flat and forming a U or V shape with the pedicel in rear view. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels oblong; 3 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; elliptic; laterally compressed; 6 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels; smooth; pilose; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6 mm long; 1.8 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; yellow and purple; 2-keeled; keeled above; keeled laterally; winged on keel; winged above. Lower glume surface convex; rugose (obscurely); rough below; glabrous, or pilose. Upper glume ovate; 1 length of spikelet; coriaceous; 1-keeled. Upper glume apex acuminate; muticous.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; hyaline; 3 -veined. Fertile lemma lanceolate; hyaline; without keel; 3 -veined. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–13 mm long overall; with twisted column. Column of lemma awn glabrous.

FLOWER Anthers 3.

DISTRIBUTION Asia-tropical: Malesia and Papuasia.

NOTES Andropogoneae. Reeder 1997.

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