Chrysopogon nigritanus (Benth.) Veldkamp

Global description

Chrysopogon nigritanus is a large, vivacious, tufted grass that grows up to 3 m tall. The leaves are rough, linear, pointed, often folded, with scabrid margin. The sheath is compressed, carinated, the ligule reduced to a line of hair. The inflorescence is a large pyramidal panicle composed of numerous purple racemes arranged in whorls. The spikelets are paired, one sessile, hermaphrodite, the other pedicelled, only male.

General habit

Large, vivacious, upright, rhizomatous, tufted grass, 1.5 to 3 m in height.

Underground system

The underground system is fasciculated and rhizomatous. The roots are not aromatic unlike Chrysopogon zizanioides.

Culm

The culm is stout, glabrous and shiny with yellow to pale green color, compressed at the base. The knots are glabrous.

Leaf

The leaf is firm, rigid and glabrous. The sheath is compressed, keeled, pale yellow. The ligule is reduced to a ring of short hairs. The limb is closely linear, terminating in a point. It is up to 1 m long and 7 to 10 mm wide. The leaves are often folded, especially at the base and then spread in the upper part, with thick ribs. The margin is smooth at the base and scabrid at the top. Both sides are glabrous.

Inflorescence

The inflorescence is a large lanceolate panicle, more or less wide, which measures 15 to 40 cm long. The racemes are numerous, whorled, 5 to 15 cm long, pedunculate, slender and fragile. Long linear internodes 6 to 9 mm long. The spikelets are grouped by 2, one is sessile and hermaphrodite, the other is pedicellate, only male. They are virtually alike, with rounded basal callus and beard (light brown hair 1 mm).
The hermaphrodite sessile spikelet is 4.5 to 7 mm long. It is greenish to purple in color. It is linear, acute, prolonged by a short and straight awn of 5 mm in length practically not excerted from the glumes. The glumes are equal, leathery, ended in a point. The lower glume acute  with rounded back, the navicular upper glume with hyaline and ciliated margins, keeled upwards and trinervated. The lower flower is empty, formed by a hyaline lemma with ciliated margins. The upper flower is fertile, with narrow lemma, hyaline slightly bidentate, prolonged by a straight or curved awn of 1 to 5 mm. Palea is hyaline, small, with ciliated margins. 3 stamens.
The male spikelet is slightly shorter than the sessile and fertile spikelet, it is awnless, purple in color. The upper glume is membranous and not spinescent.

Grain

The grain is oblong.

Worldwide distribution

Chrysopogon nigritanus occurs in tropical Africa and Southern Africa.

https://www.gbif.org/species/5677535