''Nymphaea lotus'' f. ''thermalis'' (sometimes referred to as ''Nymphaea lotus'' var. ''thermalis'') is a

form Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens. Form also refers to: *Form (document), a document (printed or electronic) with spaces in which to write or enter data ...

of '' Nymphaea lotus'' (commonly called the tiger lotus, white lotus or Egyptian white water-lily) in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Nymphaea ''Nymphaea'' () is a genus of hardy and tender aquatic plants in the family Nymphaeaceae. The genus has a cosmopolitan distribution. Many species are cultivated as ornamental plants, and many cultivars have been bred. Some taxa occur as introduc ...

''. Whilst some authorities list ''Nymphaea lotus'' f. ''thermalis'' as being synonymous with ''N. lotus'', others list it as a distinct taxon – further investigation is required to determine its precise classification. The usual

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

for ''Nymphaea lotus'' is the

Nile Delta The Nile Delta ( ar, دلتا النيل, or simply , is the delta formed in Lower Egypt where the Nile River spreads out and drains into the Mediterranean Sea. It is one of the world's largest river deltas—from Alexandria in the west to Po ...

, hence ''Nymphaea lotus'' f. ''thermaliss Romanian habitat is unusual.

Description

''Nymphaea lotus'' f. ''thermalis'' is a water lily which blooms at night – its flowers last four days and have four

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

, 19–20 white petals along with yellow

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

and stamens. There is usually a 15–30 cm gap between flowers and the surface of the water, flowers are slightly fragrant; the round leaves of the plant are 20–50 cm wide. A description was first formally published in ''Math. Természettud. Értes.'' 25(4):32, 36. 1907.

Habitat

''Nymphaea lotus'' f. ''thermalis'' is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the thermal water of the Peţa River, Sânmartin, Bihor County,

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

. The area is protected as a

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or ...

(51.0 hectares (126 acres) in size) and consists of a

rivulet A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams are ...

along with three

ponds A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from th ...

. The water has a roughly constant temperature of around 30 °C whilst the site has an average air temperature of 10–11 °C. The thermal waters have been recorded as early as 1211, but it was only in 1799 that the first record of ''N. lotus'' was made, by

Pál Kitaibel Pál Kitaibel (3 February 1757 – 13 December 1817) was a Hungarian botanist and chemist. He was born at Nagymarton (today Mattersburg, Austria) and studied botany and chemistry at the University of Buda. In 1794 he became Professor and tau ...

. Janos Tuzson proposed in 1907 that this population's unusual location could be explained by the persistent heat provided by the thermal springs could have sustained the population at a pre-ice age time when the plant would have been spreading across the warmer regions of Europe; this theory was corroborated by additional evidence provided by the identification of other endemic species.

Alexandru Borza Alexandru Borza (1887, in Alba Iulia – 3 September 1971, in Cluj) was a Romanian botanist, Greek-Catholic The term Greek Catholic Church can refer to a number of Eastern Catholic Churches following the Byzantine (Greek) liturgy, considered colle ...

was the Government minister in charge of education (and also a botanist) who made the first push for legal protection and recognition of ''Nymphaea lotus'' f. ''thermalis'' – in 1932, the

Cabinet of Romania , image = , caption=Logo of the Government of Romania , date = 1862 , state = Romania , address = Victoria PalaceBucharest , appointed = President , leader_title = Prime Minister , mai ...

declared the rivulet a nature reserve and the plant a "

national monument A national monument is a monument constructed in order to commemorate something of importance to national heritage, such as a country's founding, independence, war, or the life and death of a historical figure. The term may also refer to a spec ...

". Conservation action with the intent to preserve this population has been undertaken for many years (since at least 1940) – including the management of

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

– and the plant has been included in recent water management legislation. Whilst not held in any Romanian botanical gardens, ''Nymphaea lotus'' f. ''thermalis'' is grown at Royal Botanic Gardens Kew and at the botanic garden of

Bonn University The Rhenish Friedrich Wilhelm University of Bonn (german: Rheinische Friedrich-Wilhelms-Universität Bonn) is a public research university located in Bonn, North Rhine-Westphalia, Germany. It was founded in its present form as the ( en, Rhine ...

References

{{Taxonbar, from=Q310507 lotus f. thermalis Endemic flora of Romania Forma taxa