Resumen de Reproductive biology and ecology of Evolvulus alsinoides and Evolvulus nummularius: (convolvulaceae)
G. Lakshminarayana, A.J. Solomon Raju
The authors have found that Evolvulus alsinoides and E. nummularius grow and flower throughout the year, if the soil is wet. The pollen in both species is totally fertile and viable for 9–10 hours. This study has found that both species are facultatively xenogamous and refutes an earlier report that E. nummularius is facultatively autogamous. Furthermore, the flowers of these species resort to spontaneous autogamy during their closing time, which benefits maximization of the fruit set, but increase in the seed set rate is constrained by free styles and stigmas, which do not facilitate distinct contact with the anthers. According to earlier reports, E. alsinoides seemingly does not produce nectar, while E. nummularius definitely does not produce it. However, in this study it has been found that both species produce nectar and are pollinated by bees and butterflies, contrary to an earlier report that E. alsinoides is pollinated only by honey bees and snails. An additional finding is that both species display ballistochory, anemochory and hydrochory for seed dispersal; seeds have dormancy, as they germinate only during the rainy season. The woody rootstock also sprouts back to life to produce new foliage and reproduce sexually. These species have been found to be excellent sand binders as they usually form large patchy populations on sandy soils.
