The genera Brachiaria and Urochloa are closely related, and the two are united by some authors. See Veldkamp, Taxon 45 (1986) 319. However, this unification is not accepted by all authors - see Flora of China Vol 22 pp520-523 2006. We are following the treatment in the Flora of China and the Kew 'World Checklist of Selected Plant Families', and treating the two genera as distinct[].
Brachiaria and Urochloa are distinguished mainly by habit, Urochloa having rather more flattened, cuspidate spikelets enclosing a pronounced mucro from the upper lemma. The different spikelet orientation is also characteristic, though not obvious when the spikelets are paired. In Urochloa the lower glume faces outward, whereas in Brachiaria it lies against the rachis[]..

Common Name: Armgrass Millet

General Information

Brachiaria distachya is a more or less perennial, evergreen grass producing a cluster of slender, straggling culms 5 - 35cm tall. The stems usually form roots at their lower nodes[, ].
The plant is used to bind sandy soils, especially in coastal areas.
Brachiaria distachya is a very aggressive plant, especially in humid areas and wetlands. It has escaped from cultivation and become a weed in many parts of the tropics and is likely to become a threat in disturbed wetlands, riparian habitats, and dune systems by altering these ecosystems, displacing native species, or threatening local populations. Because it is highly competitive and produces a large volume of biomass, the species reduces species diversity and the functional diversity of indigenous macrophytes. Its allelopathic components, resistance to long periods of drought, and high germination capacity in low light conditions increase its competitive ability. When it forms extensive mats it impacts the native diversity of plants and also of fishes. Commonly invasive along margins of lakes and multiple use reservoirs, the presence of this species in water bodies generates water loss by transpiration, reduces water flow in canals, increases siltation, and generates higher maintenance costs[].

Known Hazards

None known

Botanical References

Range

Arabian Peninsula - Oman; E. Asia - Pakistan, India, Sri Lanka, Nepal, Bangladesh, Myanmar, through tropical Asia to Australia and the Pacific

Habitat

Open sandy places, inundated fields, riverbanks; at elevations to 20 metres[]. Sandy soils in disturbed places, along roads and railway lines in Eucalypt forest, dune forest, various types of woodland and shrubland[].

Properties

Weed Potential	Yes
Other Uses Rating
Habit	Evergreen Perennial
Height	0.25 m
Pollinators	Wind
Cultivation Status	Cultivated

Cultivation Details

Brachiaria distachya is adapted to humid tropical lowlands, with rain all year round or with monsoons and a dry season[, ]. It can also succeed in warm temperate climates where winters are mild and frosts are few or none[].
The plant prefers full sun but can grow under light shady conditions such as occur in old coconut plantations or orchards[]. It is adapted to a wide variety of soil types, including fertility, humidity and lighting conditions. It is common on sandy soils and sandy alluvium, and also tolerates clay soils[]. It does not tolerate waterlogging but is well adapted to sandy loam soils[]. The plant is abundant in wetlands and flooded areas, and resists temporary flooding very well, when it acquires substantial green mass that floats on top of the water[].
Plants can flower all year round[].

Edible Uses

None known

Medicinal

None known

Agroforestry Uses:

The plant is a good soil binder in sandy areas, such as coastal dunes, but because of its rampant habit it may develop into a troublesome weed[, ].
The plant can be used as a trap crop to diversify sorghum ecosystems, which may result in reduced shoot fly (Atherigona soccata) densities[].

Other Uses

None known

Propagation

Seed - sow in situ. Germination in the field occurs when soil temperatures reach 25°c in Florida, USA[].