Ludwigia hyssopifoliaLatin nameLudwigia hyssopifolia (G. Don) Exell FamilyOnagraceae Common nameSeedbox, linear leaf water primrose SynonymsJussiaea hyssopifolia G. Don (basionym); J. linifolia Vahl; Ludwigia micrantha (Kunze) Hara Geographical distributionAsia: China. South and Southeast Asia: Bangladesh, Cambodia, India, Indonesia, Lao PDR, Malaysia, Philippines, Sri Lanka, Thailand, and Vietnam. Rest of the world: Colombia, Congo-Kinshasa, Benin, Egypt, Ghana, Honduras, Iraq, New Guinea, Nigeria, Senegal, Sudan, Suriname, and West Polynesia. MorphologyAn erect annual herb, 15−150 cm tall and minutely hairy during early stage of growth. Stem: often 3-4 angled, green or purplish, and with white spongy pneumatophores arising from submerged roots. Leaf: lance-shaped, petioled, and up to 9 cm long. Inflorescence: solitary flowers, borne at axils of leaves; 4 yellow petals, elliptic, up to 3 mm long. Fruit: finely hairy, almost cylindrical, 1.75−2.5 cm long capsule. Biology and ecologyWidespread, growing in wet places, shallow pools and ditches, margins of canals and in lowland rice fields. Can produce approximately 250,000 seeds per plant; seeds released gradually and they remain floating in water up to 16 days before they sink. Seeds do not germinate under submerged conditions or when buried in soil. Seeds germinate in temperatures of 10−40ºC. Agricultural importanceCan be a serious rice weed on both clay-loam and clay soils; in lowland rice fields. ManagementCultural: hand weeding and tillage are common means of controlling this weed in rice. Chemical control: MCPA and 2,4-D as postemergence treatments and also quinclorac + bensulfuron or molinate + 2,4-D. Selected references
JLA Catindig, RT Lubigan, and D Johnson |