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.

Hyparrhenia praetermissa

HABIT Perennial; caespitose. Rhizomes short; not obviously scaly. Butt sheaths pubescent. Culms erect; 100–160 cm long. Culm-internodes smooth; distally glabrous. Leaves cauline. Leaf-sheaths glabrous on surface, or puberulous. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 2–3 mm long; truncate, or obtuse. Leaf-blades 20–45 cm long; 2–5 mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface smooth; glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence compound; linear; 20–40 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole linear; 3.25–4.75 cm long; membranous; red; pilose. Peduncle 0.6–1.5 cm long; pilose above.

Racemes 2; paired; spreading; 2 cm long; bearing few fertile spikelets; bearing 1–2 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases filiform; unequal (the longer measured); 2–4 mm long; pilose.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; ciliate; tip oblique; without appendage, or toothed.

STERILE SPIKELETS Basal sterile spikelets well-developed; on lower raceme 2 in number; 0–2 in upper raceme; male; lanceolate; 7.5–8 mm long; equalling fertile. Basal sterile spikelet glumes pilose; smooth on margins; lower glume mucronate, or awned (0.5–1.25mm).

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 7–9 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; pilose; acute; awned; one glume awned; with 2–3.5 mm long awn. 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; 7.5–8 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; 1.25–1.5 mm long; pilose; base pungent; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; without keels; keel-less except near apex. Lower glume surface flat, or concave; pilose. Lower glume hairs white. Upper glume linear; coriaceous; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of fertile lemma; hyaline; 2 -veined. Fertile lemma linear; membranous; without keel; 1 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 35–45 mm long overall; with twisted column. Column of lemma awn hirtellous; with 0.33–0.5 mm long hairs. Palea absent or minute.

FLOWER Anthers 3; 1.75–2.5 mm long. Stigmas 2.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Veldkamp 1997.

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