D. aegyptium is a grass, with characteristic 'bird's foot' digitate inflorescence, up to 50 cm tall.
Annual, never stoloniferous. Culms up to 50 cm tall, up to 5 noded, geniculately ascending, usually rooting from the lower nodes, thus giving the plants a pseudo-stoloniferous appearance, not rarely forming radiate mats, branched from the lower nodes;internodes cylindrical, glabrous, smooth, striate, exserted above, variable in length;nodes thickened and glabrous. Young shoots cylindrical or rounded. Leaf-sheaths keeled, up to 5 cm long, rather lax, striate, tuberculately hairy on the keel or quite glabrous;ligule membranous, about 1 mm long, ciliolate along the upper edge;leaf blades flat when mature, rolled when in bud, linear, tapering to a fine point, up to 20 cm long and 12 mm wide, with 3-5 primary nerves on either side of the midrib, glaucous, usually more or less densely tuberculately hairy along the margins and the keel, less conspicuously so on the adaxial surface towards the tip.
Inflorescence digitate, composed of 4-8 spreading spikes. Spikes 1.5-6 cm long, on maturity often somewhat recurved, greenish-yellow or pallid;rachis keeled, smooth near the base, scaberulous towards the apex, tip mucroniform and curved. Spikelets 4 mm long, strongly compressed, ovate, solitary, sessile, patent alternately left and right on the ventral side of the axis;dense, forming a very flat comb, usually 3-flowered;lower florets bisexual, the upper florets rudimentary;axis without terminal stipe. Lower glume 2 mm long and 2 mm wide, ovate in profile, 1-nerved, sharply keeled, keel scabrid;upper glume 2 mm long excluding the 1.5-2 mm-long awn, oblong in profile, 1-nerved, sharply keeled, keel scabrid. Rachilla slender. Lemmas 3-4 mm wide, the upper smaller in dimensions (but similar), folded about the keel which is scabrid, broadly ovate in profile, lateral nerves delicate and indistinct;uppermost lemma epaleate. Paleas about 3 mm long, 2-nerved, keels scabrid, dorsally concave, shortly bifid at the apex. Three anthers, pale-yellow, 0.3-0.5 mm long, anther cells somewhat remote, with a conspicuous connective. Caryopsis sub-triangular or sub-quadrate, laterally compressed, rugose, light-brown, apex truncate, never convex, remains of pericarp at times visible. (Fisher and Schweickerdt, 1941).
D. aegyptium is usually identified initially by the characteristic 'bird's foot' arrangement of the inflorescence with 4-8 spreading spikes. It is sometimes found as seed during inspections of seed samples.
Related invasive species
- Dactyloctenium aegyptium
Related Farm Practice
- Light
- Cropping systems
- Hosts
- Flora
- Rooting
Producing large quantities of seeds, D. aegyptium is a pioneer grass that quickly colonizes disturbed areas with light sandy soils, often near to coasts or where water accumulates. It is a common component of weed floras throughout the tropics but is rarely reported as an aggressive weed on its own. It is not on federal or state noxious weed lists in the USA and is not recorded on the ISSG database but is recorded by PIER (2016) as invasive on a number of Pacific and American islands including French Polynesia Islands, Micronesia, the Northern Mariana Islands and Hawaii. It is also listed as invasive on islands in the Mediterranean, the USA, Mexico, Costa Rica, Puerto Rico, Virgin Islands and the Lesser Antilles (Vibrans, 2009;Florida Exotic Pest Plant Council, 2011;Chacón and Saborío, 2012;Burg et al., 2012;Rojas-Sandoval and Acevedo-Rodríguez, 2015;DAISIE, 2016;USDA-NRCS, 2016).
D. aegyptium is a ubiquitous weed in many cropping systems around the world. Holm et al. (1977) classified the degree of importance of D. aegyptium on crops in different countries, in decreasing level of severity, as follows: a serious weed of cotton in Thailand;a principal weed of cotton in Australia, Kenya, Mozambique, Nigeria, Sudan, Tanzania, Uganda and USA, of sugarcane in India, the Philippines and Taiwan, of groundnuts in the Gambia and USA, of maize in Ghana and India and of rice in Sri Lanka and India;a common weed of rice in Indonesia, Nigeria and the Philippines, of coffee in Kenya and Tanzania and of tea in Taiwan and it occurs in bananas, pawpaws, cassava, citrus, sweet potatoes and millet in countries of Africa, Asia and Central America.
D. aegyptium has also been recorded in the weed flora of the following crops: aubergines in India;black gram (Vigna mungo) in Bangladesh and India;cassava in the Philippines;chickpeas in India;chillies (Capsicum) in India;cotton in Brazil, South China, India, Nepal, Thailand, USA and Zambia;cowpeas in India;finger millet (Eleusine coracana) in India;groundnuts in Bangladesh, Ghana, India, Senegal and USA;maize in India, Nigeria, Pakistan, Philippines and USA;jute in India;mint in India;mung beans (Vigna radiata) in India;okras in Nigeria;pawpaws in the Philippines;pearl millet (Pennisetum glaucum) in Burkina Faso, Mali and India;pigeon peas in India;potatoes in the Philippines;rice (transplanted) in India, Indonesia and Pakistan;rice (upland) in Cameroon, Gambia, India and Nigeria;sesame in India;sorghum in Australia, India;soyabeans in Ghana, India, Côte d'Ivoire, Pakistan, Senegal;sugarcane in India, Taiwan and Peru;sweet potatoes in the Philippines, Taiwan and USA;tobacco in India;wheat in Bangladesh and India;yams in India and the Philippines.