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.

Hemarthria natans

HABIT Perennial. Stolons present. Culms prostrate; 100–250 cm long (long); 2–5 mm diam.; rooting from lower nodes. Lateral branches ample. Ligule a ciliate membrane. Leaf-blades 4–15 cm long; 2–5 mm wide.

INFLORESCENCE Inflorescence composed of racemes; embraced at base by subtending leaf.

Racemes 1; single; smoothly terete; 3–7 cm long. Rhachis fracturing into irregular segments; flattened; glabrous on margins. Rhachis internodes cuneate. Rhachis internode tip transverse; flat.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels fused to internode; united wholly; oblong; flattened; tip rectangular.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 4–7 mm long; as long as fertile, or longer than fertile; deciduous with the fertile. Companion sterile spikelet callus truncate. Companion sterile spikelet glumes herbaceous; acute to acuminate. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 3.5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; glabrous; base truncate; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; herbaceous; 2-keeled; winged on keel; winged narrowly. Lower glume intercarinal veins distinct. Lower glume surface not waisted, or transversely waisted (near apex). Lower glume apex acute, or caudate, or acuminate. Upper glume oblong; membranous; without keels; 3 -veined. Upper glume apex acute to acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined; obtuse. Fertile lemma oblong; hyaline; without keel; 0 -veined. Lemma apex obtuse. Palea hyaline; 0 -veined; without keels.

FRUIT Caryopsis with adherent pericarp; obovoid; dorsally compressed.

DISTRIBUTION Africa: west-central tropical, northeast tropical, east tropical, and southern tropical.

NOTES Andropogoneae. FTEA.

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