Aquatic, acaulescent, rhizomatous, laticiferous herbs, usually stoloniferous with air-canals and scattered vascular bundles devoid of cambium. Roots adventitious in groups at base of petioles. Leaves simple, stipulate, usually long petiolate, heterophyllous, submerged (usually juvenile ones) and floating, spirally arranged on rhizome; venation palmate, all but one, the pinnately branched midrib, dichotomously branched; vernation involute; foliar sclereids present. Flowers solitary in leafsite or anodic side of leaf-axil, usually long-pedunculate, bisexual, with spirally arranged floral appendages. Sepals 4, free, hypogynous or epigynous. Petals usually numerous, subequal, free, innermost ones staminodal, hypogynous to epigynous. Stamens usually numerous, free, hypogynous to epigynous, with or without sterile appendages, dorsiventrally flattened, with paired microsporangia arranged adaxially; dehiscence longitudinal; pollen uniaperturate. Carpels 5 -many, partially or fully coherent and fused peripherally with receptacular tissue forming a multilocular ovary. Ovules 2-many in each carpel, anatropous, bitegmic, crassinucellate; placentation laminar. Fruit ripening under water, an irregularly dehiscent, many-seeded berry. Seeds arillate, operculate, with minute embryo, scanty endosperm and copious perisperm.
Tropical and temperate regions of the world; 5 genera and ca 70 species, 2 genera and 7 species in India.
Literature. MITRA, R.L. (1990) Nymphaeaceae. In: Fasc. Fl. India 20: 11 - 25, ff. 1 - 2. SALAR KHAN, MD. (1979) Nymphaeaceae. In: Fl. Bangladesh 9: 1. 12, tt. 1 - 4.
Notes. Nymphaeaceae (sensu lato) are often considered as a heterogeneous assemblage primarily on the. basis of gynoecial characters. The three subfamilies originally recognised by Caspary (in Engler & Prantl, Pflanzenfam. 3, 2: 4. 1888) have been accorded distinct familial status by Bessey (Ann. Missouri Bot. Gard. 2: 130 & 137. 1915), but segregated further into 5 families by Li (Am. Midl. Nat. 54: 33 - 41. 1955), Hutchinson (Fam. Fl. Pl. ed. 3, 1: 497 & 501. 1973), however, recognised only Cabombaceae and retained the other two subfamilies in the Nymphaeaceae, while Takhtajaa (Bot. Rev. 46: 225 - 359. 1980) in partial modification of his earlier views (Fl. Pl. origin & Disp. 207.1969) accepted only three families like Bessey (l.c.). Cronquist on the other hand, though originally (Evol. Class. Fl. Pl. 147 - 150. 1968) maintained only Nelumbonaceae and regrouped the remaining two subfamilies into Nymphaeaceae, he likewise changed his previous opinion (An Integrated Syst. Class. Fl. Pl. 105 - 106. 1981) and maintained four families, a view favoured by Takhtajan (l.c. 1969) earlier. These segregated families have been placed in different orders or given new ordinal ranks.
In view of the conflicting morphological evidences, some of which are fragmentary, many authors still follow Wood (J. Arnold Arb. 40: 94 - 112. 1959) in retaining Nymphaeaceae sensu lato as a single family, while considering a few genera, particularly Nelumbo as the most specialised in the whole family. Though there are growing evidences in recent times in favour of the familial concept proposed by Bessey (l.c.), in the present work families have been delimited following Cronquist (l.c. 1981).
Tropical and temperate regions of the world; 5 genera and ca 70 species, 2 genera and 7 species in India.
Literature. MITRA, R.L. (1990) Nymphaeaceae. In: Fasc. Fl. India 20: 11 - 25, ff. 1 - 2. SALAR KHAN, MD. (1979) Nymphaeaceae. In: Fl. Bangladesh 9: 1. 12, tt. 1 - 4.
Notes. Nymphaeaceae (sensu lato) are often considered as a heterogeneous assemblage primarily on the. basis of gynoecial characters. The three subfamilies originally recognised by Caspary (in Engler & Prantl, Pflanzenfam. 3, 2: 4. 1888) have been accorded distinct familial status by Bessey (Ann. Missouri Bot. Gard. 2: 130 & 137. 1915), but segregated further into 5 families by Li (Am. Midl. Nat. 54: 33 - 41. 1955), Hutchinson (Fam. Fl. Pl. ed. 3, 1: 497 & 501. 1973), however, recognised only Cabombaceae and retained the other two subfamilies in the Nymphaeaceae, while Takhtajaa (Bot. Rev. 46: 225 - 359. 1980) in partial modification of his earlier views (Fl. Pl. origin & Disp. 207.1969) accepted only three families like Bessey (l.c.). Cronquist on the other hand, though originally (Evol. Class. Fl. Pl. 147 - 150. 1968) maintained only Nelumbonaceae and regrouped the remaining two subfamilies into Nymphaeaceae, he likewise changed his previous opinion (An Integrated Syst. Class. Fl. Pl. 105 - 106. 1981) and maintained four families, a view favoured by Takhtajan (l.c. 1969) earlier. These segregated families have been placed in different orders or given new ordinal ranks.
In view of the conflicting morphological evidences, some of which are fragmentary, many authors still follow Wood (J. Arnold Arb. 40: 94 - 112. 1959) in retaining Nymphaeaceae sensu lato as a single family, while considering a few genera, particularly Nelumbo as the most specialised in the whole family. Though there are growing evidences in recent times in favour of the familial concept proposed by Bessey (l.c.), in the present work families have been delimited following Cronquist (l.c. 1981).
KEY TO THE GENERA
| 1a. Plants densely prickly; sepals, petals and stamens epigynous | 1. Euryale |
| b. Plants without prickles; sepals, petals and stamens hypogynous to perigynous | 2. Nymphaea |
