L. flava has triangular-shaped leaf and flower stalks and produces 'octopus-like' inflorescences consisting of up to 15 three-lobed yellow flowers. Its fruits are spherical and made up of cresent shaped segments that eventually split off, carried by water currents to disperse seeds to new locations (CRC for Australian Weed Management, 2003). The botanical specifics are noted as follows. It is glabrous (lacks hairs and is smooth), scapigerous (produces leafless flowering stalks) and lactiferous (contains a milky substance). It has a short stout rhizome (which measures about 3cm long and 3cm in diameter) and numerous fibrous roots. The leaves are erect, sheathing and curvinerved, and rise in clusters above the water. The petioles are thick, triangular , 90cm long and contain numerous lacunae (air spaces). The leaf sheaths narrow towards the top and the leaf blade is papery, light green, variable in shape (rounded, ovate or broad elliptic) and 6 - 20cm long (and almost as equally wide). The leaf apex is generally apiculate with a small hydathode at the tip; the leaf base is cuneate to repand-cordate; the leaf margin is undulate. There are four to six pairs of main nerves and a marginal one (sub parallel and converging towards apices), numerous secondary nerves (parallel to each other and nearly perpendicular to the midrib) and dense fine reticulations. There are about one to four peduncles (flower stalks), which are axillary, erect, triangular, flattened at the base and 120cm long. Penduncles bear, at the apex, a cluster of flowers, a ramet (vegetative plant) or both. Inflorescences are umbellate (consisting of flowers springing from a common center and arranged in a cluster), with between two to 15 flowers supported by an involucre of bracts; sometimes one or two leaves are present between the flowers. The bracts are roundish to broad-elliptic with (usually) emarginated tops. The flowers are pedicelled, actinomorphic, hermaphrodite and 2 - 4cm in diameter. The pedicel (stalk of a flower in an inflorescence) is 2 - 7cm long (3-gonous, 3-winged above, enlarging upwards and much elongated in fruit). The perianth is 2-seriate. The three sepals are persistent, imbricate (overlapping), green, obtuse in shape, 1.5 - 2cm long by 1 - 1.5cm wide, and enlarge and enclose the fruit. The three petals are pale yellow with a darker base, thin, caduceus (tend to fall off early), imbricate and broad-ovate to orbicular in shape with a rounded apex and are 2 - 3 longcm by 1 - 2cm wide. There are numerous stamens surrounded by a whorl of staminoides (filaments flattened, free, anthers basifixed, 2-celled, dehiscing longitudinally). There are 15 to 20 carpels (verticillate, laterally compressed, free, densely set, seemingly forming one superior ovary, ovules many, placentation superficial, styles wanting, stigmas sessile). The fruit are composed of fruitlets (as many as there are carpels) which are scarcely cohering, semicircular, membranous, opening along the adaxial (inner or ventral) side and having a thick abaxial (outer or dorsal) wall. There are numerous very small, horseshoe-shaped seeds, which are densly crowded together. The testa (hard outer covering or integument of a seed) is brown and spongy. Endosperm: 0 (Abhilash, 2004).
The Chromosome number for this species is 2n = 20 (Sunder Rao, 1953).
Where moisture is present year-round L. flava is a perennial herb; in ephemeral water-bodies and sites with pronounced dry seasons it is an annual (van Steenis, 1954).
is valued as an ornamental plant in some countries and cultivated in botanic gardens or private homes. Known introductions of the species for ornamental use has been documented in the USA, Singapore, Sri Lanka and Indonesia (Abhilash, 2004; Corlett, 1988; van Steenis, 1954; Senartana, 1940). In some South-East Asian countries L. flava
is used as a source of food. For example, in Java the plant is a much-esteemed vegetable, which is cultivated in rice fields and sold in markets for its young leaves, stems and flower clusters (Abhilash, 2004). In Vietnam, L. flava
occurs naturally in many bodies of water and is used as a vegetable in dishes; it is particularly popular in the Mekong Delta. Known as keo neo
or cu neo
, it is frequently gathered by ethnic Vietnamese (Kinh
) women and sold in local markets and by boat vegetable vendors. The young leaves and tops of the plant are boiled or cooked in mixed soups. The vegetable contains relatively high levels of Ca, Fe and ß-carotene, which are minerals that are frequently insufficient in the diets of women in low-income countries (Ogle et al.
2001). The leaves of L. flava
are also collected for household consumption in Bangladesh by women (Sultana et al.
It is also reported to be used as pig or cattle fodder (in Sumatra), and as green crop manure for fertilising paddies (Abhilash, 2004).
L. flava inhabits shallow swamps, ditches, pools and wet rice fields, occurring usually in stagnant fresh water (Abhilash, 2004).
Flowering and fruiting takes place throughout the year, with a single fruit producing about 1000 seeds, and a single plant producing about 1000 fruits per year (Senartana, 1940). The flowers open in the morning and close by mid-day, after which the stamens and petals disintegrate into a mucilaginous mass (van Steenis, 1954). There are no known pollinators for the plant in either South America or South east Asia. Spherical shaped fruit develops and ripens, opening along the adaxial (inner) wall; this is due to the thick curving abaxial (outer) wall. Each fruit consists of individual cresent shaped segments, known as fruitlets; the fruit and fruitlets may float for several days, scattering the numerous tiny seeds as they float downstream. The plant may also propagate clonally. A vegetative plantlet, known as a ramet, develops in the centre of an inflorescence. After the fruit has fallen, the penduncle (stalk of the inflorescence) bends over and the ramet eventually reaches the surface of the water. It then sends out its own rhizome and roots, which take root in the mud below. Alternatively, ramets may break off and float away, forming new infestations downstream (Abhilash, 2004; CRC for Australian Weed Management, 2003).
It is thought that the introduction of L. flava into India may have been due to contaminated imports of rice from rice paddies in South East Asia infested with the weed (Abhilash, 2004). It is thought that the introduction of L. flava into India may have been due to contaminated imports of rice from rice paddies in South East Asia infested with the weed (Abhilash, 2004). As well as unintentional spread of the seed via agricultural imports its use and cultivation as a food source may result in intentional spread of the plant into new countries. The latter is thought to be the cause of its spread from Java to Papua (Waterhouse, 2003).The plant was introduced into Singapore for ornamental purposes (Corlett, 1988) As well as unintentional spread of the seed via agricultural imports its use and cultivation as a food source may result in intentional spread of the plant into new countries. The latter is thought to be the cause of its spread from Java to Papua (Waterhouse, 2003). Movement of L. flava from Irian Jaya (Papua) to Papua New Guinea as a source of food is inevitable (if it isnt there already). This is also thought to be the reason for its introduction into Papua from Java (Waterhouse, 2003).
Principal source: Abhilash, P.C, School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala, India.
Waterhouse, 2003. Know your enemy: recent records of potentially serious weeds in northern Australia, Papua New Guinea and Papua (Indonesia).
Compiler: Abhilash, P.C, School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala, India & IUCN/SSC Invasive Species Specialist Group (ISSG)
Review: Abhilash, P.C, School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala, India.
Publication date: 2005-06-26
Recommended citation: Global Invasive Species Database (2018) Species profile: Limnocharis flava. Downloaded from http://www.iucngisd.org/gisd/speciesname/Limnocharis+flava on 24-09-2018.