|
Viviparous Tropical Night Bloomers Though tropical day bloomer species N. micrantha and numerous cultivars are viviparous from their pads, and several cultivars of hardies are viviparous from their flowers, only two tropical night bloomers have been reported to regularly be viviparous from their flowers. These are species from subgenus Hydrocallis, N. lasiophylla and N. prolifera. This is described by Dr. John H. Wiersema in "Reproductive Biology of Nymphaea (Nymphaeaceae)", Annals of the Missouri Botanical Garden. 75: 795-804. 1988. Page 799: "In many populations of N. prolifera and N. lasiophylla C. Martius & Zucc., however, normal flowers are replaced by tuberiferous flowers (see page 801) during part or all of the growing season. This does not seem to be temporal separation of flowering but rather a shift from sexual to asexual reproduction, the former not being successful in areas where this phenomenon has been observed." Page 801: "Two other forms of asexual reproduction have been observed, one involving proliferation of floral tissues, the other proliferation of leaf tissues. In the former, all but the outermost appendages of flowers are aborted, and an enlarged tuber is formed centrally which gives rise to whorls of leaves and additional tuberifferous flowers. A few orders of branching may result, leading to the formation of a large number of small tubers. The tubers readily abscise, float briefly, and eventually become rooted and develop into mature plants. This process occurs regularly in the neotropical N. lasiophylla and N. prolifera of suhg. Hydrocallis (Wiersema, 1987). Similar abortive flowers have been reported in other syncarpous Nymphaea (Bose, 1961; Mohan Ram & Nayyar, 1974; Majeed Kak, 1977; Mitra & Subramanyam, 1982) but only as an unusual occurrence. This is a very effective method of reproduction and dispersal, particularly in N. prolifera, which commonly inhabits lowland savannas subject to periodic flooding." Click browser "Back" to return to Names or Gallery
Page |