GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Andropogon itremoensis

HABIT Perennial; caespitose. Rhizomes elongated. Culms geniculately ascending; 30–45 cm long. Culm-internodes distally glabrous. Culm-nodes bearded. Lateral branches lacking, or sparse. Leaves cauline. Leaf-sheaths without keel; striately veined; glabrous on surface. Leaf-sheath oral hairs scanty, or lacking. Ligule a ciliolate membrane; 1 mm long; membranous; erose; obtuse. Leaf-blade base cordate. Leaf-blades erect; straight; lanceolate; flat; 5–12 cm long; 4–6 mm wide; stiff; mid-green. Leaf-blade surface glabrous; hairless throughout. Leaf-blade margins scaberulous; glabrous, or ciliate; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; 4–7.5 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs 0.75–1.5 mm long. Rhachis internodes filiform; 1.8–2.2 mm long; 0.33 length of fertile spikelet. Rhachis internode tip transverse; cupuliform; with simple rim. Raceme-bases filiform.

Spikelets squeezed between internode and pedicel; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; without a translucent median line; ciliate; with 0.75–1.5 mm long hairs.

STERILE SPIKELETS Basal sterile spikelets well-developed; smaller than fertile. Basal sterile spikelet lemmas awnless.

Companion sterile spikelets well-developed; male; lanceolate; 9.5–11 mm long; longer than fertile. Companion sterile spikelet glumes chartaceous; glabrous; acute; muticous, or mucronate. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 5.5–6.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square; 1 mm long; pubescent; base obtuse; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 5.5–6.5 mm long; 1 length of spikelet; chartaceous; 2-keeled; keeled dorsally; wingless; 14–18 -veined. Lower glume surface deeply depressed; glabrous. Lower glume apex attenuate. Upper glume lanceolate; membranous; 1-keeled. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma margins ciliate. Lemma apex lobed; 2 -fid; incised 0.33–0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 12–15 mm long overall; with twisted column. Column of lemma awn glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: western Indian ocean.

NOTES Andropogoneae. Vorontsova 2013.

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