Plants annual or weakly perennial. Culms 5-170 cm, prostrate
to erect; compressed, often branching; internodes hollow. Sheaths glabrous
or scabrous; ligules 2-8 mm, membranous, attenuate, becoming lacerate
at maturity; blades 3-50 cm long, 2-7 mm wide, glabrous or scabrous,
those of the flag leaves sometimes exceeding the panicles. Panicles (1.5)10-105
cm long, 0.5-22 cm wide, with 3-35 racemose branches, bases of the panicles
sometimes remaining enclosed in the upper leaf sheaths at maturity; branches 1.5-20(22)
cm, ascending to reflexed. Spikelets 5-12(14) mm, with 6-20 florets. Lower
glumes 1-3(4.9) mm; upper glumes 1.8-5.5 mm; lemmas 2-6
mm, sometimes with a dark spot near the base, apices acute to truncate,
sometimes emarginate to bifid, unawned, mucronate, or awned; paleas somewhat
sericeous along the veins; anthers 1-3, 0.2-2.7 mm. Caryopses 0.8-2.4
mm, elliptic to ovate or obovate. 2n = 20.
Leptochloa fusca grows in warm areas throughout the world. The two American
subspecies, subsp. uninervia and subsp. fascicularis,
are usually distinct, but they intergrade repeatedly with subsp. fusca.
FNA 2003, Gould 1980
Common Name: Malabar sprangletop Duration: Annual Nativity: Native Lifeform: Graminoid General: Annual to weakly perennial grass, prostrate to erect stems 5-170 cm, compressed, often branching with hollow internodes; sheaths glabrous or scabrous. Vegetative: Blades 3-50 cm long, 2-7 mm wide, glabrous or scabrous, the flag leaves sometimes exceeding the panicles; ligules 2-8 mm, membranous, attenuate, lacerate at maturity. Inflorescence: Panicles 10-105 cm long, 0.5-22 cm wide, with 3-35 racemose branches, bases of the panicles enclosed in the upper sheaths at maturity; branches 1-20 cm, ascending to reflexed; spikelets 5-12 mm with 6-20 florets; lower glumes 1-3 mm, upper 1-6 mm, lemmas 2-6 mm, sometimes with a dark spot near the base, apices acute to truncate, sometimes emarginate, mucronate to awned; paleas sericeous along the veins. Ecology: Found on moist to marshy soils, often in alkaline soils below 5,000 ft (1524 m); flowers June-October. Distribution: Warm areas throughout the world; native to Africa, Asia, Australia, N. America, and S. America; found in every state in the US. Notes: Until very recently this taxon was placed within the genus Leptochloa. Look for it under that name even in relatively recent texts. It is a robust annual grass with noticably compressed stems where they emerge from the ground, and panicles of long spikelike branches that are often partly sheathed even at maturity. In our region there are two subspecies: ssp. uninervia and ssp. fascicularis. The former is told apart by the slightly longer anthers; the 5-10 mm spikelets; and the dark green to lead-gray lemmas which are obtuse to truncate at the tip. Subsp. fascicularis is distinguished by the panicles being partially enclosed in the upper sheath; the upper leaves which are taller than the panicle; and the mature lemmas are often smoky white with a dark spot in the basal half, with tapering tip. Another annual, Leptochloa viscida, is also found in the Sororan Desert; it has consistently short-awned lemmas (vs. frequently unawned or mucronate lemmas in L. fusca), smaller panicles, an often prostrate and much-branched growth habit, and often reddish florets (vs. L. fusca's whitish or gray florets). A halophyte, L. fusca has potential for use in bioremediation of saline soils. Ethnobotany: Used as fodder for livestock around the world. Etymology: Leptochloa is from Greek leptos, slender and chloe or chloa, grass, while fusca means dark or brown. Synonyms: Festuca fusca, Diplachne fusca, Poa fusca, Uralepis fusca Editor: SBuckley 2010, AHazelton 2015