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.

Agenium

HABIT Perennial. Culms erect; slender (1/1); 15–65.83–120 cm long. Ligule an eciliate membrane (2), or a ciliolate membrane (1). Leaf-blades stiff (1), or firm (2).

INFLORESCENCE Inflorescence composed of racemes; terminal (2), or terminal and axillary (1).

Racemes single (1), or paired (1), or digitate (2); erect (1), or drooping (2). Rhachis fragile at the nodes; flattened. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases brief (1), or filiform (1), or linear (1).

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform.

STERILE SPIKELETS Basal sterile spikelets well-developed.

Companion sterile spikelets well-developed; separately deciduous. Companion sterile spikelet callus square (2), or cuneate (1).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (2), or lanceolate (1); subterete; 5–6.782–8 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate (1), or linear (2); pilose (1), or bearded (2); base pungent; attached obliquely.

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate (2), or elliptic (1); coriaceous; without keels; 8 -veined. Lower glume surface with a longitudinal median groove; without pits; pubescent (2), or pilose (1). 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 (2), or oblong (1); hyaline; 2 -veined (1/1); truncate (2/2). Fertile lemma linear; cartilaginous; without keel; wingless; 1 -veined. Lemma surface unwrinkled; without grooves. Lemma apex acute; awned; 1 -awned. Principal lemma awn geniculate. Column of lemma awn glabrous (1), or pubescent (2). Palea absent or minute.

DISTRIBUTION South America.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.