Description

Scientific name: Eichhornia crassipes

Family: Pontederiacieas

Common name: Water Hyacinth, Camalote, Water Lily.

Origin: South America (Amazon and Orinoco basins)

The Water Jacinto, (Eichhornia crassipes) is an aquatic plant with large leaves and colorful purple flowers. The leaves have fluffy petioles that behave like floats because they have a fabric with air-filled cells that allow the plant to stay on the surface by grouping into large intertwined root formations.

Flowering lasts a couple of days, the petals have organs of production of nectar to attract insects such as bees that perform pollination, it has been proved in the Guadiana. Although, pollination processes are also known without pollinating insect, through wind or by self-pollination, because the species is self-compatible (Gopal, 1987), which is a typical strategy of adaptation to the colonization of new environments.

Each plant forms a series of fruits (capsules), in number of up to 20 per inflorescence.  Each can contain 3 to 450 seeds, these of an approximate size of 1×3 mm. The seeds need for germination not to be buried (high rates of light), and alternating temperatures (5-40o C) (Gopal, 1987), (Study of the seed bank of Eichhornia crassipes in the Guadiana Basin).

It inhabits lagoons and rivers, especially those which are enriched with nitrogen and phosphorus. The optimum growth temperature is 25-30 oC. Growth ceases when the water temperature is above 40 oC or below 10 oC, being able to tolerate short freezing periods.

It spreads vegetatively and by seed. After flowering the peduncle curves and the fruits ripen, so the seeds initially fall into the water. They are seeds capable of germinating immediately but can remain dormant for 15-20 years, and then germinate. Germination is stimulated by conditions of aerobiosis and alternating temperatures. This occurs when sharp phenomena of water level descent take place, both in rivers and rice paddies.

Seedlings root in the mud initially but are sometimes dragged or floating and are moved to different places. From very early stages of growth, the more mature leaf growth axillary buds have the ability to transform into stolons that grow horizontally and form child plants.

Eichhornia crassipes has leaves that perform photosynthesis in a particular way (photosynthesis C4). This makes it an extremely effective plant with growth rates that have been calculated from 1,012 to 1,077. Other studies suggest that its ability to increase biomass is more than 12% per day. The time required, to double its number of individuals or biomass ranges from 6 to 15 days. Productivity can also be expressed in terms of 100-500 g of fresh weight per square meter per day, 1000-5000 kg per hectare per day, or 400-700 tons per hectare per day. The total biomass can be up to 42 kg per square meter or 420 tons of fresh weight per hectare. As the dry weight is normally 5-7%, this represents about 2.5 kg of dry weight per square meter or 25 tons of dry matter per hectare.