Commelina diffusa Burm.f - COMMELINACEAE - Monocotyledon

Synonym : Commelina nudiflora auct. non L.

Common name : spreading dayflower.

Botany Biology Phenology Ecology Distribution Cultural control Biological control Chemical control

Botany :

Description :	Terrestrial, annual or perennial, prostrate herb, up to 100 cm long, rooting at nodes. Roots fibrous, white or brown. Stem rounded, solid, glabrous, succulent. Stipules absent. Leaves simple, alternate spiral, sessile, lanceolate, elliptic, or ovate, glabrous on both sides, margins entire, succulent, apex acute, base clasping, parallel veined, leaf sheats present, rounded in cross section, hairy, ligules absent. Flowers bisexual, grouped in axillary or terminal inflorescences, covered by a spathe. The spathe edges are free in the base, long from 1 to 3,5cm, shortly pedunculated and hairless. Flowers single or few, stalked, blue, petals 3, free. Fruit a capsule, opening with 3 valves.
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.

Biology :

It propagates by seeds and by layering of segments of broken stems.

Phenology :

Flowering May to December: fruiting September to February.

Ecology :

C. diffusa is commonly found in moist fields, along ditches, on waste land and under bamboo, on soils rich in clay or humus, from sea-level up to 2000 m altitude.

Distribution :

Indian Continent, S.E.Asia, Malesia, Korea, Taiwan, New Caledonia.

It is particularly difficult to control by cultivation, partly because broken pieces of above and below ground stems readily take root. With hand weeding, it is necessary to uproot all the plant from the soil to ensure effectiveness.

Biological control :

Very few natural enemies have been reported to attack C. diffusa and, of this, only two agromyzid leaf miners from the Americas appear promising (Amauromyza sp. and Liriomyza commelinae from Diptera family).

Chemical control :

Post-emergence application of 2,4-D at 500 g/ha or Almix 4 g/ha.

Uses :
In Peninsular Malaysia, the leaves are widely used for poulticing sores.
In Indonesia, the crushed leaves and stems are used for irregular menstruation.
Dirty wounds are poultice with the mucilage from the stems.
The leaves are edible and may be used as a vegetable.
In some areas, leaves used as an ointment and absorptive.
Leaves are used as an abortifacient, also used against infected wounds.
Very variable as to pubescence, In West Java there is a form with densely, shaggy bracts and hair under the leaf surface.

Remarks :
C. diffusa differ from C. benghalensis by the absence of hairs on the margin of leaf sheath, by a stretched spathe glabrous and none fused. The flowers are long pedunculated.

References :
-Lavit Kham. 2004. Medicinal plants of Cambodia.
-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.
-Tavatchai Radanachaless, J.F.Maxwell. 1994. Weeds of soybean fields in Thailand. Multiple Cropping, Center Publications. Thailand.

Top of the page