Common name : Sedge, smallflower umbrella
Common name in Hindi : Dila, motha
Common name in Urdu : Ghoin
Bangla English Hindi Urdu
Diagnostic characters
Biology
Ecology and distribution
Nuisance
Weed control
Botany
Uses/Remark
References
C. difformis is a small, tufted, annual sedge native of the Old World tropics. It may be distinguished mainly by the dense, globose heads composed by many radiating spikelets.
In tropical areas, C. difformis apparently can flower and produce seeds all year long if the soil moisture is sufficient. This plant reproduces by seeds which are produced in large quantities. One plant could complete the vegetative cycle in one month and produce a new generation of weeds during the second month, producing 50.000 seeds with about 60% germination.
C. difformis is widespread throughout southern Europe, Asia, Central and North America, Africa and the islands of the Indian and Pacific oceans. It is mainly a weed of the tropics and subtropics but can be found from lat 35°S to 45°N. The plant normally grows in flooded or in very moist soils. It is primarily a weed of paddy or flooded rice. It is frequently found in small pools, along rivers, canals and streams, in open wet places and in grassy swamps. It grows best in rich, fertile soils but can growin poor sandy or clay soils of unused lands or in fallow rice fields.
C. difformis is a widespread and serious weed of paddy rice. It is important because it produces abundant seed and rapidly becomes a dominant weed in the fields. Producing abundant plants per unit area, the plant form dense and solid mats of vegetation in the young rice crop. This weed appears to be more of a competitor for water and nutrients than for light. The ability of the plant to complete a vegetative and reproductive cycle within a month or so makes it especially competitive in a crop which requires at least 90 or more days to reach maturity.
- Chemical Post-emergence application of 2_4-D at 500 g/ha or Almix at 4 g/ha.
Habit
C. difformis is tufted, smooth, annual or rarely perennial sedge, 10 to 75cm high.
Roots
Numerous, fibrous, reddish.
Culm
Rather weak or tender, triangular, slightly winged, smooth, 1 to 3mm thick.
Leaves
Linear, few, weak, rather abruptly acuminated, smooth or slightly rough at the top, usually shorter than the plant, 2 to 5mm wide, sometimes reduced to sheaths. Sheaths tubular united the lower sheaths straw-colored to brown.
Inflorescence
In dense globose, umbellate heads, simple or compound, 8 to 15mm across, with numerous (more than 40) stellately spreading spikelets. The inflorescence rather loose, simple or compound subtended by one, two, three or four leaflike bracts which are contracted or spreading, one may be almost erect, up to 25cm long. The umbel rays 1 to 5cm long, some sessile, some long peduncled. Spikelets linear to oblong-linear, compressed by slightly swollen, obtuse, 2.5 to 8mm long, 1 to 1.25mm wide, 10 to 30 flowered, remarkable for the numerous, very small, almost orbicular, concave glumes which occurs in two opposite rows, closely packed, at first rich brown, dirty green or blackish. Stamens one or two, style branches three.
Fruit
Achenes elliptic to slightly obovate, acutely subequally triangular in cross section, lightly pitted, shining, straw-colored, yellowish brown or pale brown, about 6mm long.
- Holm L. G., Plucknett D. L., Pancho J. V., Herberger J. P. 1991. The world’s worst weeds. Distribution and Biology. East-West Center by the University Press. Hawaii.
Top of the page