Blue Grass
Blue Grass


1 200 - 2 500 mm tall

50 - 100 mm long

6 - 8 mm long

Leaf blade:
500 mm long, 5 - 20 mm wide

Tall annual or perennial, tussock grass; culms erect, up to 3 m tall, more or less stout, about 0.6 cm 
in diameter, glabrous, many-noded, producing flowering branches from the third node upward;
leaves glabrous or softly pubescent, rarely villous or tomentose; sheath tight, striate; ligule short, 
rounded or truncate, glabrous or somewhat hairy on back, rarely exceeding 0.2 cm long; lamina linear 
to lanceolate-linear in the lower leaves, usually from a much attenuated base and there often forming 
a terete petiole, tapering to a fine point, over 30 cm long, up to 1.6 cm broad, glaucescent or reddish, 
margin scabrous; inflorescence in panicles up to 6 or more primary mixed 2 to many rayed tiers, 
the inner ray of lower or lowest tiers often up to 30 cm long (sometimes up to 60 cm long), 
with 2–4 secondary few-rayed tiers; spatheoles pale green, herbaceous, lanceolate-oblong, 
6.5–7.5 cm long, at length more or less tightly enrolled and turning red; racemes in pairs, 3.5–6.5 cm
long, one sessile, the other with a bare base about 0.4 cm long, joints stout, cuneate-clubshaped; 
sessile spikelets greenish or tipped brown or red, about 0.8 cm long including the obtuse callus; 
scantily bearded at base; glumes equal; awn 1.3–2.2 cm long, twisted well below middle, column brown,
bristle pale; pedicellate spikelets male and glabrous. Flowers April–June in tropical Africa.
Ranging from Warm Temperate Moist through Tropical Dry to Wet Forest Life Zones, gamba grass is 
reported to tolerate annual, precipitation of 8 to 27 dm (mean of 9 cases = 12.2), annual temperature 
of 15 to 32°C (mean of 9 cases 21.4), and pH of 4.3 to 8.3 (mean of 5 cases = 6.1). In grassy places, 
damp places, low-lying meadows, edge of thickets; often forming large areas. Also thrives in areas with 
long dry season up to 7 months long. Adapted to a wide range of soil types, with different ecotypes 
adapted to various soils varying from sandy to heavy black cracking clays. Very drought resistant and 
not to susceptible to frost.
Native and widely distributed in tropical Africa, north and south of Equator; introduced to other tropical 
areas, as tropical Queensland, Brazil, India, and western Australia.
Considered one of the best grazing grasses in northern Nigeria and northern Ghana. Makes valuable hay
and green fodder grass in central and northeastern Brazil. In Africa, this grass grows in large tufts up 
to 2 m tall. Young shoots are preferred, but cattle will eat it up to time of flowering. Stems, flattened, 
are used for coarse matting (weaving grass mats and thatching). Plants are useful for planting on banks 
for erosion control.

Image Credits:
Colin Wilson

  • Bogdan, A.V. 1969. Rhodes grass. Commonwealth Bureau of Pastures and Field Crops, Hurley, Berkshire, England, Herbage Abstracts 39(1):1–13.
  • Bowden, B.N. 1963., Studies on Andropogon gayanus Kunth. I. The use of Andropogan gayanus in agriculture. Empire J. Exper. Agric. 31(123):267–273.
  • Duke, J.A. 1978. The quest for tolerant germplasm. p. 1–61. In: ASA Special Symposium 32, Crop tolerance to suboptimal land conditions. Am. Soc. Agron. Madison, WI.
  • Duke, J.A. 1981b. The gene revolution. Paper 1. p. 89–150. In: Office of Technology Assessment, Background papers for innovative biological technologies for lesser developed countries. USGPO. Washington.
  • Gohl, B. 1981. Tropical feeds. Feed information summaries and nutritive values. FAO Animal Production and Health Series 12. FAO, Rome.
  • Hagger, R.J. 1974. The effect of quantity, source, and time of application of nitrogen fertilizers on the yield and quality of Andropogon gayanus at Shika, Nigeria. J. Agr. Sci. Cambr. 84:529–535.
  • Tetteh, A. 1972. Comparative dry matter yield patterns of grass/legume mixtures and pure stands (Andropogon gayanus, Digitaria decumbens, Centrosema pubescens, Desmodium leiocarpum). Ghana J. Agr. Sci. 5(3):195–199.


Andropogon Gayanus