Andropogon andringitrensis

HABIT Perennial; culms solitary, or caespitose; clumped loosely. Culms geniculately ascending; 40–60 cm long. Culm-internodes abbreviated and closely packed at the base; distally glabrous. Culm-nodes bearded. Lateral branches ample. Leaves cauline. Leaf-sheaths without keel; striately veined; glabrous on surface. Leaf-sheath oral hairs scanty. Ligule a ciliolate membrane; 1–2 mm long; membranous; truncate. Leaf-blades erect; linear, or lanceolate; 10–20 cm long; 2–3 mm wide; mid-green. Leaf-blade surface glabrous; hairless except near base. Leaf-blade margins smooth, or scaberulous; ciliate; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3; paired, or digitate; arcuate; 4–8 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs 0.5–1.5 mm long. Rhachis internodes filiform; 1.5–2.5 mm long; 0.33 length of fertile spikelet. Rhachis internode tip transverse; cupuliform; with simple rim. Raceme-bases filiform; 2–5 mm long; hirsute.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 3 mm long; without a translucent median line; ciliate; with 0.5–1.5 mm long hairs.

STERILE SPIKELETS Basal sterile spikelets well-developed; male.

Companion sterile spikelets well-developed; male; lanceolate; 6.5–8.8 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; winged on keels; 11 -veined; erose, or dentate; muticous, or mucronate. Companion sterile spikelet lemmas enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 5–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus brief; 0.5 mm long; pubescent; base obtuse; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 5–7 mm long; 1 length of spikelet; chartaceous; 2-keeled; keeled laterally; winged on keel; winged narrowly; 14–18 -veined. Lower glume surface concave; glabrous. Lower glume apex erose, or dentate; attenuate. Upper glume lanceolate; membranous; 1-keeled. Upper glume apex dentate; 2 -fid; mucronate, or awned; 1 -awned. Upper glume awn 0.5–1.5 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma lanceolate; hyaline; without keel. Lemma margins ciliate. Lemma apex lobed; 2 -fid; incised 0.66 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–12 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FRUIT Caryopsis with adherent pericarp; oblong, or ovoid.

DISTRIBUTION Africa: western Indian ocean.

NOTES Andropogoneae. Vorontsova 2013.

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