Panicum brevifolium L.

Global description

Panicum brevifolium is a small annual creeping grass, and branched at the nodes. The flowering stalks are vertically erect, reaching 20 to 50 cm in height. The leaves are reduced, with lanceolate or oval lanceolate lamina, 2 to 8 cm long, broadly rounded and embracing the stem at the base and acute apex. The faces are glabrous to loosely pubescent. The ligule is a short truncated membrane. The inflorescence is an oval panicle, loose, whose base is sheathed in the last leaf, reaching 5 to 15 cm long. The spikelets are acute oval, 1.5 to 2 mm long, glabrous or hairy, flattened ventrally and convex dorsally. The glumes are almost equal, the lower are smaller than the spikelet, 3-veined, the upper of same size as the spikelet, 5-veined. The internal flower is male or sterile, formed from a lemma similar to upper glume. The external fertile flower is a little shorter than spikelet, the lemma is cartilaginous, smooth, pale.
 
First leaves

First leaves simple alternate, broadly oval, with clasping enlarged and asymmetric base, and acute to acuminate apex. The prefoliation is rolled. The leaf blade is very short, 2 to 3 cm and proportionately wide, 1.5 to 2 cm, glabrous, with scabrous margin. The first leaves are nested in one another with a spreading leaf blade.
 
General habit

Branched creeping annual grass, with ends erect vertically, 20 to 50 cm high.
 
 
Underground system

Fibrous roots at the base of the plant and numerous adventitious roots at the nodes of the grass stem in contact with the ground.

Culm

The grass culm is slender, geniculate ascending, cylindrical, easily rooting at the lower nodes, glabrous, sometimes purplish.
 
Leaf

Leaves are simple, alternate with rolled aestivation. The cylindrical sheath is extensively ciliate on margin, glabrous elsewhere. The ligule is a short truncated membrane. The leaf blade is short, shaped like a teardrop, lanceolate to oval lanceolate, 2 to 10 cm long and 18 to 25 mm wide. It is flat and thin, glabrous to loosely pubescent. The base is widened round, embracing the stem, with acuminate apex, and scabrous margin.
 
Inflorescence

The inflorescence is an oval panicle, 5 to 18 cm long and 2.5 to 12 cm wide, loose, whose base remains sheathed in the last leaf for a long time. The branches are slender, solitary or irregularly spaced. The pedicels of the spikelets are very thin and of variable length
 
Spikelet

The spikelets are solitary, acute oval, 1.5 to 2 mm long, glabrous or hairy, green to purple, hunchback and flattened stomach. The glumes are slightly uneven, the lower glumes is shorter that the spikelet, hyaline, narrow, trinerved. The upper glume is green, as long as the spikelet, elliptical 5-veined, and concave. The internal flower is male or sterile, formed from a lemma similar to the upper glume and an oblong, bi-lobed and bi-keeled palea. The external flower is fertile, acute oval, shorter than the spikelet, lemma and palea cartilaginous and smooth.
 
Grain

The grain is widely oval, 0.6 mm long

Origin

Panicum brevifolium is native to Asia and Africa.

Worldwide distribution

Common species in Africa, the Indian Ocean islands and Asia. It has been introduced into Brazil.

 

https://www.gbif.org/species/4153922