GrassBase - The Online World Grass Flora


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

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

Agenium majus

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms erect; 100–120 cm long. Culm-nodes bearded. Ligule an eciliate membrane; 3 mm long. Leaf-blades convolute; 15–30 cm long; 3–6 mm wide; stiff. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 3–6; digitate; drooping; 5 cm long. Central inflorescence axis 1–2 cm long. Rhachis fragile at the nodes; flattened; ciliate on margins. Rhachis internodes linear; 4 mm long. Rhachis internode tip oblique; flat. Raceme-bases linear; 5–10 mm long.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; flattened; 4–5 mm long; ciliate.

STERILE SPIKELETS Basal sterile spikelets well-developed; 18 in number; male; lanceolate; 12 mm long; larger than fertile. Basal sterile spikelet glumes chartaceous.

Companion sterile spikelets well-developed; male; lanceolate; laterally compressed; 12 mm long; longer than fertile; separately deciduous. Companion sterile spikelet callus square; 0.5 mm long; obtuse. Companion sterile spikelet glumes chartaceous; distinctly veined; 18 -veined; acute. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 6.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; 1–1.5 mm long; bearded; base pungent; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 6.5 mm long; 1 length of spikelet; coriaceous; without keels; 8 -veined. Lower glume surface with a longitudinal median groove; pubescent; hairy above. Lower glume apex obtuse. Upper glume lanceolate; coriaceous; without keels. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 3 mm long; hyaline; truncate. Fertile lemma linear; 2 mm long; cartilaginous; without keel; 1 -veined. Lemma apex entire; acute; awned; 1 -awned. Principal lemma awn geniculate; 60 mm long overall; with twisted column. Column of lemma awn pubescent. Palea absent or minute.

FRUIT Disseminule comprising a spikelet.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Andropogoneae. WDC.

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