Nuphar lutea
Nuphar lutea (L.) Sm.
Nymphaeaceae – Water Lily Family
Conservation status. Endangered [EN B2ab(i,ii,iii,iv)]. BDA.
Morphology and biology. Perennial aquatic herb with creeping rhizome. Stem not developed. Leaves of two types – partly floating, ovate, with a deep, acute basal sinus; submerged leaves with thin transparent lamina, cordate, with wider sinus. Flowers single, on long pedicel above the water. Petals spathulate, numerous,3–4 times shorter than sepals, yellow. Fruit spongy, berry-like capsule. Fl. VI– IX, fr. VIII–X. Reproduction by seeds and vegetative means.
Habitats and populations. In slow waters, bogs, lakes. Due to the long-term melioration most localities reported in literature have been destroyed. The species used to cover thousands of decares in the marshes close to the Danube. Now, the fragments from these old populations are preserved near the mouth of Veleka river (from the mouth of the river up to 10 km upward the population covers 1500 m2 forming patches along the river banks), in protected areas and in some draining canals.
Distribution in Bulgaria. Black Sea coast (Shablensko Lake, lower course and estuary of Kamchia and Veleka rivers, Velyov Vir locality), NE Bulgaria (protected area Kalimok-Brashlen), Danubian Plain (canals around Kozlodui town and Orsoya villages). In the past it occurred in Thracian Lowland (Maritsa river); up to 200 m alt.
General distribution. Europe, C and SW Asia, Caucasus, Siberia.
Threats. Degradation of the habitats due to the draining and pollution of the water bodies, climate change, development of aggressive water tourism.
Conservation measures taken. Protected species according to the national Biodiversity Act. Some of the localities are in the territory of Ustieto na Reka Veleka, Shablensko Ezero and Kalimok-Brashlen Protected Sites, Velyov Vir Managed Nature Reserve as well as in sites of the European ecological network Natura 2000 in Bulgaria. A program for reintroduction of the species in the extinct occurrence in Persinski swamps is being implemented.
Conservation measures needed. Investigation of the size and area of the populations, monitoring of the state of the populations, building of small water bodies, reconstruction of some Danube marshes.
References. Jordanov 1970; Vassilev 1984.
Authors: Dimitar Peev & Sonya Tsoneva
