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.

Hyperthelia

HABIT Annual (5), or perennial (2). Culms erect (3/3); 100–233.7–570 cm long; without nodal roots (2/4), or with prop roots (4/4). Leaf-sheath auricles absent (5), or erect (5). Ligule an eciliate membrane. Leaf-blade base without a false petiole (6), or with a false petiole (1). Leaf-blades linear, or lanceolate (1).

INFLORESCENCE Synflorescence compound; scanty (1), or linear (1), or paniculate (3), or fastigiate (2). Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted (2), or embraced at base by subtending leaf (2), or enclosed (3). Spatheole linear (1), or lanceolate (6); scarious.

Racemes paired; side by side (6), or with abortive upper raceme represented by a single sterile spikelet (1); erect (3), or ascending (1), or spreading (1), or deflexed (3); bearing few fertile spikelets; bearing 1 fertile spikelets on each (6), or 2–5 fertile spikelets on each (1). Rhachis fragile at the nodes. Rhachis internodes filiform (6), or linear (1). Rhachis internode tip oblique; flat. Raceme-bases filiform; subequal (1), or unequal (the longer measured); extended into an oblong appendage (5), or extended into a flask-like appendage (2).

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; tip rectangular (1), or oblique (6).

STERILE SPIKELETS Basal sterile spikelets well-developed.

Companion sterile spikelets well-developed; deciduous with the fertile (6/6). Companion sterile spikelet callus indistinct (1), or cuneate (6). Companion sterile spikelet glumes muticous (4), or awned (6).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 7.47–13.97–35 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; pubescent (1), or pilose (4), or bearded (2); base acute (1), or pungent (6); attached obliquely.

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; coriaceous; without keels; 6 -veined (2/5), or 7–9 -veined (1/5), or 10 -veined (3/5), or 11 -veined (2/5), or 12–14 -veined (3/5). Lower glume surface with a longitudinal median groove; without pits; glabrous (1), or puberulous (1), or pubescent (5). Lower glume apex dentate; 2 -fid; setaceously attenuate (2/2); muticous (6), or mucronate (1). Upper glume oblong; coriaceous; without keels; 3 -veined. Upper glume apex emarginate (2/4), or acute (1/4), or setaceously attenuate (1/4); muticous (3), or mucronate (3), or awned (3); 1 -awned (2/2).

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong (6/6); hyaline; 2 -veined (6/6). Fertile lemma linear; hyaline; without keel; wingless; 3 -veined (6/6). Lemma surface unwrinkled; without grooves. Lemma margins eciliate (2), or ciliate (5). Lemma apex dentate (6), or lobed (1); 2 -fid; incised 0.1–0.1667–0.25 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate. Column of lemma awn puberulous (1), or pubescent (2), or hirtellous (4). Palea absent or minute.

FLOWER Anthers 3 (1/1).

FRUIT Caryopsis with adherent pericarp (1/1); fusiform (1/1).

DISTRIBUTION Africa, or North America (1), or South America (1).

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