Practical
Plants

Eichhornia crassipes

Water Hyacinth

a perennial member of the Eichhornia genus in the family Pontederiaceae.

No photo available

Taxonomy and growth

Life cycle
perennial
Flower type
hermaphrodite

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

Eating the plant, which is reported to contain HCN, alkaloid, and triterpenoid, may induce itching[6]. Fresh plants contain prickly crystals[6]. Plants sprayed with 2,4-D may accumulate lethal doses of nitrates[6].

Edible uses

This section contains historical Plants For A Future notes marked noncommercial.

Young leaves and petioles - cooked[2][3][7]. Virtually tasteless[2][3]. Said to be used as a carotene-rich table vegetable in Formosa. Javanese sometimes cook and eat the green parts and inflorescence[6]. Flower spikes - cooked[2][3].

Plant part
Leaves

Material uses

This section contains historical Plants For A Future notes marked noncommercial.

Water hyacinths are potentially an excellent source of biomass. Through an anaerobic fermentation process, polluted hyacinths can be converted to the natural gas methane - a costly process that may become more economical as supplies of underground natural gas are depleted[6]. Dried and cleansed plants can be used as fertilizer and plant mulch[2][6]. Eventually, living aquatic plants might serve aboard long-distance manned spacecraft, absorbing wastes and converting carbon dioxide to oxygen, then being themselves converted into food[6]. The plant can be cultivated for use in wastewater treatment, and can be incorporated into a system where the biomass is harvested for fuel production[6]. Since this biomass is a by-product of wastewater treatment, it has a positive environmental impact, and thus poses no threat as competitor to food, feed, or fibre-producing plants[6]. Wilted water hyacinth, mixed with earth, cow dung, and woodashes in the Chinese compost fashion, can yield useful compost in just two months[6]. Although potential yields are incredible, so are the costs of removal or attempted eradication of this water weed. Standing crops have been estimated to produce 100-120 tonnes per hectare per year[6].. Under ideal conditions, each plant can produce 248 offspring in 90 days[6]. Water hyacinth roots naturally absorb pollutants, including such toxic chemicals as lead, mercury, and strontium 90 (as well as some organic compounds believed to be carcinogenic) in concentrations 10,000 times that in the surrounding water[6]. In Africa, fresh plants are used as cushions in canoes and to plug holes in charcoal sacks[6].

Product or use
Biomass
Product or use
Pollution

Environment

Range
Tropics. Naturalized in central and southern Portugal[8].
Habitat
Water courses[2]. Moist and boggy areas at elevations of 200 - 1500 metres in Nepal[7].
Light
full sun
Shade tolerance
light shade
Water
moderate
Soil textures
sandy, loamy, clay
Soil pH
acid, neutral, alkaline
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

Seed - Seeds can tolerate submersion or desiccation for 15 years and still germinate[6]. Scarification, but not light, may be required for germination[6].

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

240, 200 Prefers growing in a sunny but cool pool[5]. Water Hyacinth is reported to tolerate an annual precipitation of 82 to 270cm, an annual temperature range of 21.1 to 27.2°C and an estimated pH in the range of 5.0 to 7.5[6]. The leaves are killed by frost, and plants cannot tolerate water temperatures in excess of 34°C[6]. This species is not very cold-hardy, tolerating temperatures down to about 0°c[5]. It requires greenhouse protection over winter in Britain[1]. Plants can be grown outdoors in the warmer parts of the year and then be potted up in moist compost during long spells of cold weather[5]. A very invasive weed of water courses in the tropics[5], causing great environmental problems in many areas where it has become naturalized. Subsistence farmers in Bangladesh face disaster when rafts of water hyacinth weighing up to 300 tonnes per hectare float over their rice paddies. As the floods recede, the weeds remain on the germinating rice, thus killing it[6]. Engineers have estimated that the Panama Canal would be impassable within three years without continuous aquatic weed control measures[6]. Azotobacter chroococcum, a Nitrogen-fixing bacteria, may be concentrated around the bases of the petioles but doesn't fix Nitrogen unless the plant is suffering extreme Nitrogen-deficiency[6].

References

  1. F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00

    ↩

  2. Cribb. A. B. and J. W. Wild Food in Australia. Fontana 1976-00-00 ISBN 0-00-634436-4

    ↩1↩2↩3↩4↩5

  3. Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169

    ↩1↩2↩3

  4. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

  5. Phillips. R. & Rix. M. Conservatory and Indoor Plants Volumes 1 & 2 Pan Books, London. 1998-00-00 ISBN 0-330-37376-5

    ↩1↩2↩3↩4

  6. Duke. J. Handbook of Energy Crops - 1983-00-00

    ↩1↩2↩3↩4↩5↩6↩7↩8↩9↩10↩11↩12↩13↩14↩15↩16↩17↩18↩19↩20↩21

  7. Manandhar. N. P. Plants and People of Nepal Timber Press. Oregon. 2002-00-00 ISBN 0-88192-527-6

    ↩1↩2

  8. ? Flora Europaea Cambridge University Press 1964-00-00

    ↩

Edit this page