Stenotaphrum dimidiatum (L.) Brongn.

Global description
 
Stenotaphrum dimidiatum is a vivacious creeping grass. Stolons are prostrate, branched and take root at the nodes. The ends of the stems are erect and are 10 to 40 cm high. The leaves have a compressed sheath and a short ciliated ligule. The lamina is linear, 3-20 cm long and 5 to 12 mm wide, rounded or obtuse at the apex. The terminal inflorescence is a fake spike with wide and flat axis, which can measure 15 cm long. The spikelets are between 4 to 5 mm long and is inserted by 2 to 8 in distantly way along the axis of the spike.
 
First leaves
 
First leaves simple, alternate, distichous, with compressed, flat, carinate sheath, very short, ciliated ligule, short, bent or flat with rounded top leaf blade. They have a folded prefoliation.
 
General habit
 
Prostrate herb, strongly stoloniferous to rhizomatous to forming a dense mat. The flowering axes straightened up 6-40 cm high.
 
Underground system
 
Fibrous roots that develop at the nodes of runners. Rhizomes can also be present.
 
Culm
 
The culm of the grass is highly compressed, hollow, glabrous, 10-40 cm high.
 
Leaf
 
Simple and alternate leaves, arranged distichously. The sheath is highly compressed and keeled. Ligule is reduced to a very short ciliated rim of 0.5 mm. The leaf blade is flat or folded, linear. It measures 3 to 20 cm long and 5 to 12 mm wide. It is rounded or obtuse at the top and rounded at the base. It is glabrous with smooth margin.
 
Inflorescence
 
The inflorescence is an erect false spike, rigid, and more or less robust. It measures 3 to 10 cm long and 2 to 3 mm wide, but can reach 15 cm long and 5 to 6 mm wide. It is flat and winged, the wings alternating either side of a twisting midrib. Each wing terminates with a short point.
 
Spikelet
 
The spikelets are lanceolate oblong, 4 to 5 mm long. They are smooth with a small widely rounded lower glume not exceeding 1/5 of the length of the spikelet. The upper hull is as long as the spikelet or slightly shorter. It is very concave, acute at the top with 7-9 ribs. The lower flower is male, the size of the spikelet, with a tough lemma, flattened on the back, 5-7 veined, pubescent at the top. The upper flower is hermaphrodite, slightly smaller than the lower flower with a lemma and a palea cartilaginously smooth.
 
Grain
 
Broadly elliptical to oblong grain, dorsally compressed (plano-convex). It is 3 mm long and 1.2 mm wide.

Origin

Stenotaphrum dimidiatum is native to East and South Africa, the Indian Ocean islands, India and South East Asia.

Worldwide distribution

This species has been introduced in various African countries (Algeria, Benin, Burkina Faso, Guinea, Ghana) and in the Pacific Islands (New Caledonia, Samoa, Polynesia, Vanuatu)

https://www.gbif.org/fr/species/4119008