Synonymes : Commelina nudiflora L., Commelina longicaulis Jacq.
Common name : Spreading dayflower
Common name in Bengali : Manaina, kanainala
Common name in Hindi : Kankana
Bangla English Hindi Urdu
Diagnostic characters
Biology
Ecology and distribution
Nuisance
Weed control
Botany
Uses/Remark
References
Commelina diffusa is a fleshy, herbaceous, creeping and more or less ascending, annual or perennial herb. The stems are supple frequently touching the soil and developing root at the nodes. The leaves are fleshy, bright green; the lamina is little hairy or glabrous and narrower than in Commelina benghalensis L. The flowers are bright blue enveloped by a membranous and glabrous spathe with free margins contrary of Commelina benghalensis L. The fruit is a capsule with 3 lobes, but only 2 open in mature stage.
Annual to perennial herb. It propagates by seeds and by layering of segments of broken stems.
It develops in deep soils, shadow, cool and wet situations; often in littoral areas or at medium altitude. Native of the Old World tropics, originating in Asia. Now a pantropical weed, extending somewhat into temperate zones.
Their sprawling, creeping habit, coupled with their ability to root readily at the nodes, causes problems in perennial as well as vegetable and cereal crops, competing with them for light and nutrients. C. diffusa and also C. benghalensis have a great persistence in cultivated lands and it is difficulty to control. The plants form dense, pure stands, smothering out other plants, especially low-growing crops.
- Chemical
Post-emergence application of 2_4-D at 500 g.I/ha or Almix 4 g/ha.
Habit
Annual or perennial herb.
Ascending or creeping, glabrous and branched; rooting at nodes and growing in patch.
Roots
White fibrous roots, fasciculate, also present at the nodes in contact with the soil.
Stem
Stems are cylindrical, thick and glabrous
Leaves
Simple alternate leaves, ovate to lanceolate, bright green, glabrous, 2 to 5cm long and 0.5 to 2cm wide. Lamina sessile or almost, connected with a membranous sheathes, cylindrical, surrounding the stem and ciliate on margins. Numerous and parallel nerves, but little visible. Summit of the leaf gradually acuminated and the base rounded. Hairless faces.
Inflorescence
2 to 4 pedicelled flowers (1 to 3cm) appearing from a folded spathe, broad, heart shaped, rounded at base, gradually tapering above to a rather acute apex. The spathe edges are free in the base, long from 1 to 3,5cm, shortly pedunculated and hairless. 5 sepals of which 3 are free and green, and 2 are connected with the base; 3 free petals, bright blue colour. Lateral petals rounded in the summit and filiform in the base; lower petal smaller. 5 to 6 stamens hairless of which 3 are fertile and 2 (or 3) sterile.
Fruit
Capsule three-celled. Long from 4 to 5mm. Lower one indehiscent with 1 seed; dorsal one dehiscent with 2 seeds.
Seeds
5 seeds per capsule, reticulate-ribbed, elongated, brownish, long from 2 to 3mm.
Seedling
First leaves elliptic, 2 to 3cm long and 1 to 2cm wide. Limb subsessile, hairless, with parallel nerves and the margin not wavy.
Commelina diffusa differ from Commelina benghalensis by the absence of hairs on the margin of leaf sheath, by a stretched spathe glabrous and non fused. The flowers are long pedunculated.
- Le Bourgeois T., Jeuffrault E., Grard P., Carrara A. 2001. AdvenRun V.1.0. Les principales mauvaises herbes de La Réunion. CD-ROM. Cirad, SPV. France.
- 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.
- Galinato M., Moody K., Piggin C. M. 1999. Upland rice weeds of South and Southeast Asia. IRRI. Philippines.
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