Panicum humile Steud.

Panicum humile is an annual weed, in diffuse clumps, flowering abundantly, reaching up to 40 cm high. The stems are erect, slender, smooth and branched at almost all nodes. The branches end in inflorescences. The leaves have a linear lamina, acute at the top, plan, 3 to 15 cm long and 3 to 5 mm wide. The inflorescence is a developed oval panicle, loose, 12 cm long. The branches are solitary or in groups, erect at the start then spreading obliquely. The spikelets are acute oval, 1.7 to 2 mm long, glabrous, often reddish or purple, with slender and sinuous pedicel, of variable length of 1.5 to 7 mm.
 
General habit

Grass in diffuse clumps, highly branched, and with abundant flowers, 10 to 40 cm high.
 
Underground system
 
Roots are fibrous.
 
Culm
 
Culm is cylindrical, hollow, erect, slender, glabrous, and branched at the nodes. The nodes are glabrous.
 
Leaf
 
Simple alternate leaves. The sheath is glabrous, sometimes ciliated on the margins. Ligule represented by a truncated membrane, lacerated at the top. The lamina is linear, with acute apex, plan, 3 to 15 cm long and 3 to 5 mm wide. Both sides are glabrous. The margin is full and smooth.
 
Inflorescence
 
The inflorescence is an oval panicle, loose, up to 12 cm long, with the branches erect at first then obliquely spreading, solitary or verticillate The pedicels of the spikelets are slender, sinuous and the length varying from 1.5 to 7 mm.
 
Spikelet
 
The spikelets are oval, acute, 1.7 to 2 mm long, glabrous, often reddish or purple. The lower glume is acute oval or slightly acuminate, reaching 3/4 the length of the spikelet, it has three ribs. The upper keel is as long as the spikelet, with 5 ribs. The internal flower is sterile and reduced to a lemma similar to the upper glume. The external flower is fertile, slightly shorter than the spikelet, 1.5 mm long, oblong obtuse, with crustaceous lemma and palea, smooth, shiny, pale or more or less colored gray.
 
Grain
 
Oblong grain, 1 mm long.