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.

Chrysopogon rigidus

HABIT Perennial; caespitose; clumped densely. Culms erect; 130–150 cm long; 3–4 -noded. Ligule a fringe of hairs. Leaf-blades 30–50 cm long; 3–5 mm wide.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; lanceolate; 20–27 cm long; 8–10 cm wide. Primary panicle branches 3–5 -nate; whorled at most nodes; simple; 0.5–1 cm long.

Racemes 3–4.5 cm long; bearing few fertile spikelets; bearing 3–4 fertile spikelets on each. Rhachis fragile at the nodes; scabrous on surface. Rhachis internodes filiform; 4–11 mm long. Rhachis internode tip oblique.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 2–5 mm long; 0.5 length of internode; scaberulous.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; linear, or lanceolate; dorsally compressed; 4–5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; 3 -veined; scaberulous; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear, or lanceolate; laterally compressed; compressed slightly; acute; 6–9 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; bearded; base acute; attached obliquely.

GLUMES Glumes dissimilar; reaching apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; cartilaginous; without keels; 3 -veined. Lower glume surface muricate; rough on veins. Upper glume lanceolate; cartilaginous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume awned; 1 -awned. Upper glume awn 1–2.5 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 6 mm long; hyaline; 2 -veined. Fertile lemma linear; 2 mm long; hyaline; without keel. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; flexuous; 8–10 mm long overall. Palea lanceolate; 2.5 mm long; hyaline; 0 -veined; without keels.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; 3–5 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Simon 1994.

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