C. dactylon is a perennial grass, with underground rhizomes and on the ground runners (Cabrera, 1968;Covas and Salvai, 1970). The runners spread horizontally and bear nodes with internodes of about 10 cm length. They may be flattened or cylindrical, mostly unhaired. Each node roots in the soil and produces short culms (tillers), up to 25 cm high, but develop into prostrate runners under less dense conditions. The almost unique character of the Cynodon genus of at least two and often three leaves at each node can be seen on the extended runners. This immediately distinguishes it from other perennial weeds with comparable growth pattern such as Panicum repen s and Paspalum distichum (Perez and Labrada, 1985).
The rhizomes are mainly in the top 10 cm of the soil but may penetrate to a depth of 35 cm (Perez and Labrada, 1985;Phillips and Moaisi, 1993).They may be twice as wide as the runners and this is one of the variable characters in populations (0.2-0.9 cm). Each node is covered by a white cataphyl. Runner or rhizome nodes may bear up to three viable buds.
Leaves have an alternate-distal pattern of distribution along the runners. Leaf blades are open up to the base, unhaired, similar or shorter than the length of the internode. The ligule is very short but with a conspicuous fringe of white hairs. Leaf blades are green to dull-green, from 1 to 15 cm depending on node, lanceolate, and forming almost a 90° angle with the leaf blade, finely parallel-ribbed on both surfaces, without a conspicuous midrib (Rosengurt et al., 1960). The width and pilosity of the weed blade may be used to distinguish populations of the weed (Oakley, 1999).
The inflorescence is supported on a culm up to 25 cm high and consists of a single whorl of 3-7 narrow racemes, each 3-8 cm long. Spikelets are 2-2.5 mm long in two rows, closely appressed to the rachis. Glumes are one-nerved, the lower almost as long as the spikelet, the upper half to three-quarters as long. The lemma is silky pubescent on the keel, palea glabrous. Caryopses are sub-eliptical, compressed and brownish, brilliant coloured (Kissmann, 1991).
The seedling has a hairy ligule, bearing 0.5 mm hairs. Pilosity increases as the seedling grows.
Related invasive species
- Cynodon dactylon
Related Farm Practice
- Pastures
- Soil
- Forestry
C. dactylon is a stoloniferous grass widely naturalized in tropical and subtropical regions of the world. This species is a C 4 grass included in the Global Compendium of Weeds (Randall, 2012) and it is listed as one of the most “serious” agricultural and environmental weeds in the world (Holm et al., 1977). It is a fast-growing grass that spreads by seeds and stolons and rapidly colonizes new areas and grows forming dense mats. As with many other African grasses, this species has the potential to alter ecosystem functions by altering fire regimes, hydrological cycles, biophysical dynamics, nutrients cycles, and community composition (D’ Antonio and Vitousek, 1992). C. dactylon is very drought tolerant by virtue of rhizome survival through drought-induced dormancy over periods of up to 7 months. After dormancy, it has the ability to easily re-sprout from stolons and rooted runners. Plants also recover quickly after fire and can tolerate at least several weeks of deep flooding (Cook et al., 2005). Currently, C. dactylon is listed as invasive in many countries including Australia, Indonesia, Singapore, Cambodia, Vietnam, USA, Mexico, Costa Rica, Puerto Rico, Chile, Colombia, Uruguay, Argentina, Brazil and many islands in the Pacific Ocean such as Hawaii, Fiji, and French Polynesia among others (see distribution table for details).
C. dactylon is treated by Holm et al. (1977) as the second most important weed in the world (after Cyperus rotundus), a status justified by its occurrence in virtually every tropical and subtropical country and in virtually every crop in those countries. In Holm et al. (1979) it is listed as a 'serious' or 'principal' weed in no less than 57 countries. A list of crops in which C. dactylon is, or could be, a problem weed would include virtually every crop of the tropics and subtropics and most temperate crops. The crops in which it is most commonly a major problem are those of the subtropics that are planted in wide rows, for example, cotton, sugarcane, tobacco, citrus, olive, deciduous fruit, forestry and ornamental species and many vegetables, but also some closer-planted but less competitive crops such as rice, lucerne, mixed lucerne and grass pastures, onion and jute (Labrada, 1994).