Chrysopogon zizanioides (L.) Roberty

Global description

Chrysopogon zizanioides is a cespitose vivacious grass with a glabrous, upright stem which can reach up to 300 cm in height. The leaves are long and flat, with scabrous margins. The ligule is limited to a scariose ring.  The inflorescence is a pyramidal panicle (oblong) of 15-40 cm long with 4-8 cm long racemes inserted at almost every node of the panicle.

General habit

Erect grass, in a dense clump of 150-300 cm high with erect culms.

Underground system

The underground system consists of short rhizomes and long and dense fasciculate roots . The roots are aromatic.

Culm

The culm is erect, cylindrical, glabrous, and reaches 150-300cm in height. The nodes are usually under the leaf sheath.

Leaf

The sheaths are glabrous, elliptical in section and keeled, strongly imbricated at the base and fan-like arranged. The ligule is a scarious ring. The leaves are pale green. The lamina is linear, glabrous and with scabrous margin. They are 30-100 cm long and 4-10 mm wide. The leaves are inclined, even folded at the base.

Inflorescence

The inflorescence is composed of threadlike racemes of 4-8 cm long, verticillate, with fragile rachis. The panicle is generally purplish, with the main axis a little scabrous. 6-10 whorls with each about 20 racemes. Racemes with 5-13 pairs of spikelets and a terminal triad.

Spikelet

Spikelets are arranged in pairs, one sessile and the other pedicellate, both of the same size or with the pedicellate spikelet slightly shorter. The internodes and pedicels are slightly scabrous. The sessile spikelet is hermaphroditic, linear-lanceolate, even linear and laterally compressed. It is 3.5-5mm long. The glumes, both lanceolate, are dissimilar. The callus is rounded and glabrous. The lower glume is muriculate, spiny, with 3-5 veins. The upper glume is keeled, cartaceous, mute with spinose main vein.  Glumes are leathery and smooth or scaberulous. Basal sterile floret without a palea with a 2-nerved lemma, ciliate on the margin and oblong. The upper fertile floret has an oblong, mutic, 2-3 mm long upper lemma without veins. The palea is smaller, 0.3-0.5mm long. There are 3 anthers of 2-3mm.The pedicellate spikelet is staminate (composed only of male florets), linear, almost smooth.

Origin

Chrysopogon zizanioides is native to Asia. 

Worldwide distribution

This species is now pantropical. It is now found in several tropical areas, including Central Africa, islands of the Indian Ocean, South and Central America, and South Asia. It can be found in some parts of North America as well.

https://www.gbif.org/fr/species/5677150