Axonopus compressus (Sw.) P.Beauv.

Global description

Axonopus compressus is a vivacious grass, turfting, with rhizomes and stolons rooted at the nodes. The grass stems are erect, slender, glabrous, constricted, 15 to 60 cm high. The leaves have compressed, keeled sheaths, glabrous but with ciliated margin. The leaf blade is oblong linear, with strongly ciliated pectinate margin, with 3 clearly visible light-coloured veins. The inflorescence consists of 2 to 5 racemes, thin, more or less spread, 3 to 9 cm long, inserted on a short axis. The oval acute spikelets are solitary, sessile, 2.5 to 3 mm long
 
First leaves

On regrowth, the young shoots have leaves clustered at the base, arranged in a distichous way but with rolled prefoliation, and overlapping sheaths on one another. The lamina is linear, broad, with obtuse apex and strongly ciliated pectinate margin, and 3 clearly visible lignt-coloured veins. The ligule is membranous, truncate, denticulate

General habit

Perennial tufting grass, with erect stem, forming a dense close mat, 15 to over 60 cm high

Underground system

The plant emits rhizomes and stolons; dense fibrous roots develop at the nodes of the shaft. 

Culm

The culm is erect, slender, compressed and hairless, with hairless or hairy nodes.

Leaf

The leaves are simple, alternate, in distichous arrangement. The sheath is compressed, keeled, hairless with ciliated margin. The lamina is oblong-linear, obtuse at the top, flat or folded, 4 to 12 cm long and 4 to 12 mm wide, hairless on both sides, shiny on the upper face, sometimes pectinate ciliated on more or less ondulated margin, with 3 clearly visible light-coloured veins. Ligule reduced to a short truncated denticulate membrane.

Inflorescence

The inflorescence is sub-digitate, formed from 2 to 5 sessile racemes, slender, laterally compressed, and obliquely erect or spreading, 3 to 9 cm long and 1 mm wide, inserted on a short axis.

Flower

Spikelets are solitary, sessile, lanceolate, acute, 2 to 3 mm long. They are arranged alternately in two rows along the axis of the raceme. The inferior glume is absent. The superior glume is the size and shape of 5-veined spikelet with fine and loose hair. The lower sterile flower, is reduced to a lemma similar to an upper glume but with 4 veins (the center vein being suppressed). The superior fertile flower is significantly shorter than the spikelet (4/5), elliptical, obtuse, finely pubescent at the top, a pale yellow in color. The lemma and palea are finely cartilagenous, palea obtuse, covered by the lemma on the sides.

Seed

The grain is elliptical, obtuse, about 1, 5 mm long, yellow-brown

Origin

Native of tropical America.

World Distribution

Widely naturalised in the humid tropics and subtropics, especially west tropical Africa, South Africa, India, the Philippines, Indonesia, Australia and the Pacific Islands. Africa: west tropical, west-central tropical, east tropical, southern tropical, and western Indian ocean. Asia-temperate: China and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central. North America: southeast USA and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

https://www.gbif.org/species/2705924