Trapa natans Linnaeus, 1753

Trapa natans imageSynonyms: Trapa longicarpa Jank., 1961

Common names: Bulg: Voden orekh, Julyun; Russ: Vodyanoy orekh plavayushchiy; Ukr: Vodyany gorikh plavayuchy

Order: MYRTALES

Family: TRAPACEAE

Taxonomic descriptions: Annual water herb. Submarine stem is 40-150 cm length. Leaves 3-4 cm length, 3-4.5 cm width, floating, wide diamond-shaped, from below with hairs along veins. Petioles are 3-10 cm length, cylindrical or with oblong swellings near leaf blades. Fruits (diameter 6-10 mm) with firm cover, four-corned.

Trapa natans arealIUCN Status:
    World level: VU
    Black Sea Regional level: VU
    Subregion level: VU

Distribution:

Habitats type, Critical habitats, Limiting factors: Geographic area of species covers both Europe and Mediterranean. The species grows in stagnant or slightly flowing waters 50-250 cm mostly in river valleys, in silt soils. Occurs in pure growth or with other water plants.

Biology: Probably, the species has obligate self-fertilization: there is no data about cross fertilization. Fruits are distributed by flowing waters, mammals and birds. Seeds have a good germination power (up to 40-50 years), annually only a part of them shoot. Flowering during VI-VII. Fruit-bearing - VIII-IX. Reproduction only by seeds.

Population trends: Populations are numerous, particularly in the “Dunajskiye plavni” reserve (Ukraine).

Threats: Drying of wetlands, chemical pollution, output for animal feeding.

Conservation measures taken: The species has been entered in the Red Data Books of Ukraine (1996) and Bulgaria (1984), protected in the Danube delta (Ukraine and Romania).

Conservation measures proposed: To create new protected zones.

References:

  1. Lucas, G. 1977. List of rare, threatened and endemic plants in Europe. Strasbourg. 286 p.
  2. Peev, D. 1979. Flora na NRB. VII. Sem. Trapaceae, pp.444-446.
  3. Rare and vanishing plants of the USSR/Ed. by Ac. A. Takhtajan. - Leningrad, 1981. - 264 p.
  4. Red Data Book of Russian Soviet Federal Socialist Republic. Plants. - Moscow, 1988. - 590 p.
  5. Red Data Book of Bulgaria. Vol. 1. Plants. - Sofia, 1984. - 447 p.
  6. Red Data Book of Ukraine. Vegetable Kingdom. - Kyiv, 1996. - 606 p.
  7. Tchopik V.I. Rare and vanishing plants of Ukraine. - Kiev, 1978. - 216 p.
  8. Zaverucha B.V., Andrienko T.L., Protopopova V.V. Protected plants of Ukraine.- Kiev, 1983.176 p.

Compiled by: S.Dyatlov, M. Filipova, T.Vasilieva