Taxonomic name: Urochloa maxima (Jacq.) R.D. Webster
Synonyms: Panicum gongylodes Jacq., Panicum hirsutissimum Steud., Panicum jumentorum Pers., Panicum laeve Lam., Panicum maximum Jacq., Panicum maximum var. coloratum C.T. White, Panicum maximum var. gongylodes (Jacq.) Döll, Panicum maximum var. maximum, Panicum maximum var. pubiglume K. Schum., Panicum maximum var. trichoglume Robyns, Panicum polygamum var. gongylodes (Jacq.) E. Fourn., Panicum trichocondylum Steud., Urochloa maxima var. trichoglumis (Robyns) R.D. Webster
Common names: buffalograss (English), capime guiné (French), fataque (French), green panic (English), Guinea grass (English), herbe de Guinéa (French), panic élevé (French), saafa (Tonga), talapi (Cook Islands), tinikarati (Cook Islands), vao Kini (American Samoa), vao Kini (Samoa), yerba de Guinea, zacate Guinea
Organism type: grass
Although Urochloa maxima is the accepted name for this species, it is still widely known as Panicum maximum. Urochloa maxima is a native of tropical Africa where it occurs from sea level to 1,800m. It is used as a forage grass and its ability to tolerate a wide range of habitats make it a very productive species. Urochloa maxima has become prevalent in Samoa and Tonga and it is a problem species in Guam and Hawaii. Although it is a favourable grass in many areas it can also form dense stands and displace native species.
Urochloa maxima is described as a tufted perennial, often with a short creeping rhizome, variable 60-200cm high, leaf blades up to 35mm wide tapering to a fine point; panicle 12-40cm long, open spikelets 3-3.5mm long, obtuse, green or purplish, glumes unequal, the lower one being one-third to one fourth as long as the spikelet, lower floret usually male or empty depending on the variety. Upper floret (seed) distinctly transversely wrinkled lemma and palea. The grain is about 2mm long. (Skerman and Riveros, 1990; Bogdan, 1977).
agricultural areas, riparian zones, ruderal/disturbed
Ranging from Tropical Dry to Wet Forest Life Zones, guinea grass is reported to tolerate annual precipitation of 6.4 to 42.9 (mean of 40 cases = 18.5), annual temperature of 12.2 to 27.8°C (mean of 40 cases = 23.4), and pH of 3.5-4.3 to 8.4 (mean of 33 cases = 5.9) (Duke, 1978, 1979. Handbook of Energy Crops. unpublished. Cited in James A. Duke. 1983.). Grows naturally in open grasslands, usually forming colonies under or near trees and shrubs, frequent in woodland bush thickets, and on abandoned cultivated land, fields and on waste lands, from sea level to 1800m in East Africa. Suited to areas with annual rainfall from 87 to 100cm. With sufficient moisture, plants grow extremely rapidly, providing much biomass. Grows well on a wide variety of well-drained soils. Does not thrive in areas subject to prolonged waterlogging or flooding, nor on saline soils. Not resistant to frost. Somewhat tolerant to shade and grows under trees or in stands of low bush. Grows in moderately dry ground and is drought-resistant, but will not tolerate dry periods longer than 4 months.
Urochloa maxima forms dense stands in open pastures and disturbed areas. Guinea grass can suppresses or displace local plants on fertile soils in pastures Its resistance to drought also means it builds up a dangerous mass of plant material so when fires occur, the blaze is fiercer and native plants which have not built up fire-tolerance are wiped out. As guinea Grass can survive fires, it can dominate the ground after a fire.
Guinea grass is a most productive forage grass in tropical America and South East Asia, valuable for pasture, green-forage, hay, and silage. Reported to be diuretic and preventative, guinea grass is a folk remedy for tympanitis (Duke and Wain, 1981, cited in James A. Duke. 1983 ). It's seeds can provide food for birds, the long leaves can also provide nesting material for birds, (Tan, Ria. 2001). Guinea grass is considered as a suitable plant to stop soil erosion on slopes (it has dense root mats) while providing valuable fodder (Tan, Ria. 2001).
Guinea grass is a very variable species. Many distinct types occur naturally in Africa and about a dozen varieties have been named. It spreads very slowly by seed but needs fertile soil to dominate. In the wet tropics weeds can quickly dominate guinea grass pastures unless pastures are well managed (Hare, M., pers. comm., 2003). Guineagrass, is reported to tolerate periods of drought, grazing, low pH, shade, slope, virus, but not waterlogging, and weeds. Will not withstand long periods of severe desiccation or long periods of hard continuous grazing. This grass is of primary economic importance in many tropical countries, including East Africa, Hawai‘i, Virgin Islands, Puerto Rico, Southeast Asia and South America (James A. Duke. 1983). It can survive quick-moving fires which do not harm the underground roots (Tan, Ria. 2001).
Native range: Africa; widely introduced and naturalized.
Known introduced range: American Samoa, Commonwealth of the Northern Mariana Islands, Cook Islands, Federated States of Micronesia, Fiji, French Polynesia, Galapagos Islands, Guam, Hawai‘i, Kiribati, New Caledonia, Niue, Norfolk Island, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Vanuatu, Wallis and Futuna Islands. Australia, China, Japan, Korea, Taiwan, Thailand, Vietnam, Malaysia, Philippines, Indonesia Mauritius, Jamaica, continental USA, Caribbean.
Introduction pathways to new locations
Agriculture: Introduced to almost all tropical countries as a source of animal fodder. (Tan, Ria. 2001)
Local dispersal methods
Agriculture (local): Planted as fodder for grazing animals. (Duke, 1983)
On animals (local): Seeds are dispersed by wind. (PIER, 2002)
Preventative measures: A Risk Assessment of
Urochloa maxima (Panicum maximum) for Hawai‘i and other Pacific islands was prepared by Dr. Curtis Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service. The alien plant screening system is derived from Pheloung et al. (1999) with minor modifications for use in Pacific islands (Daehler et al. 2004. The result is a score of 17 and a recommendation of: "Likely to cause significant ecological or economic harm in Hawai‘i and on other Pacific Islands as determined by a high WRA score, which is based on published sources describing species biology and behaviour in Hawai‘i and/or other parts of the world."
Physical: Hand pulling / grubbing also works, but spraying seems easier (Starr, F and Starr, K., pers. comm., 2003).
Chemical: "Susceptible to glyphosate and readily controlled by drizzle applications. Young plants are susceptible to selective grass-killers" (Motooka et al., 2002, cited in PIER, 2002).
Biological: Plants die rapidly under close continuous grazing (James A. Duke. 1983).
In South Africa, it is suspected to cause a sheep disease ("dikoor"), perhaps in conjunction with a smut. The plant is said to cause fatal colic if eaten too wet or in excess. Traces of HCN occur in stems and leaves, more in the roots.
Seeds profusely but seeds are of low germination, often empty and do not survive long. The seeds are dispersed short distances by wind. Fire will sweep through stands of this grass but it regenerates rapidly from underground rhizomes (Hare. M., pers. comm., 2003).
Reviewed by: Dr. Michael Hare Faculty of Agriculture, Ubon Ratchathani University, Warin Chamrab, Ubon Ratchathani, Thailand
Compiled by: IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Thursday, 26 January 2006