Chloris gayana

Rhodes grass


Chloris gayana

Kunth 1830

pronounced: KLO-riss gay-AH-nuh

(Poaceae — the grass family)

synonym — Chloris abyssinica

Hochst. ex A.Rich. 1850

pronounced: KLO-tiss a-biss-IN-ih-kuh

common name: Rhodes grass

Chloris may be from the Greek χλωρος (chloros), green, or may be named for Χλωρις (Chloris), a Greek nymph associated with spring, flowers and new growth. She was abducted by Zephyros, the god of the west wind, and later married him. They had a son named Karpos, a youth renowned for his beauty. His name means ‘fruit’ (cf. Latin carpus). This story is a natural metaphor: the west wind heralds the new growth of spring, which then bears fruit. There is a story, told in Nonnus’s Dionysiaca, telling of Karpos’s love for another youth, Kalamos, who was the son of Maiandros, the god of the Meander River. While the two youths were competing in a swimming contest in that river, Karpos drowned. In his grief, Kalamos allowed himself to drown as well, and was then changed into a water reed, whose rustling in the wind was a sign of lamentation.

Gayana is named in honour of Claude Gay (1800–1873), French traveller and naturalist. In 1828 he went to Chile, and spent the next 14 years studying the botany, zoology and meteorology of that country, and also of parts of Peru, Brazil and Argentina. On his return to Paris he published in Spanish, at the expense of the Chilean government, his magnum opus, Historia Fisica y Politica de Chile, in 24 volumes, as well as a large 2 volume atlas containing 315 plates. I presume that the ‘Rhodes’ of the common name is in honour of Cecil Rhodes, of Rhodes Scholarship fame, as this grass is native to much of southern Africa, but I have no actual evidence of this. The grass is also found naturalized in temperate and tropical Asia, North and South America, the Pacific islands and Australasia. Here, it is found in all of the mainland states. It is a grass of open woodland and grassland, riverine and lake margins, and seasonally waterlogged plains, on a wide variety of soils.

The distinguishing features of this grass are its ligule, a membranous rim with hairs on the edge; and an inflorescence of 7–20 digitate spikes, straw-coloured at maturity. The spikelets overlap in 2 rows on one side of the rachis. There are 2 or 3 awns per spikelet, about the same length as the spikelets. The grass grows to about 2 m tall.

It is used in permanent pastures or as a short- to medium-term pasture ley to restore soil structure, improve organic matter levels, and to reduce nematode numbers. It makes good hay if cut at or just before very early flowering, but is generally not suitable for silage. It develops good ground cover, and effectively controls erosion once established.

Rainfall in its natural range varies from about 500 to 1,500 mm per year. In cultivation, it is usually planted in areas with a rainfall of 700–1,200 mm, but has been successful at lower annual averages. It does not thrive in areas with more than 1,800 mm rainfall. It is popular in irrigated pastures, particularly where irrigation water may be too saline for other species. Generally, it has poor shade tolerance. Stands develop quickly, and can be grazed 4–6 months after planting, although highest production is attained in the second year. Since feeding value declines rapidly after flowering, it is important to maintain the stand in a leafy condition by fairly regular defoliation. Some late-flowering varieties have been developed that allow a greater flexibility in this regard. The grass grows well in association with legumes.

This is a food plant for the larvae of the Sugarcane Stem Borer Bathytricha truncata.


Physical and Political History of Chile


Photographs taken 2010, Picnic Bay
Page last updated 7th November 2018