Reproductive Phenology of Lagerstroemia Speciosa (lythraceae) in Southern Western Ghats, India

Lagerstroemia speciosa known as “natural plant insulin” effective on the treatment of diabetes due to its insulin-like activity, and because of other bioactive components has been widely exploited from its natural habitat and hence shows a decline in population along with low regeneration. Flowering and fruiting phenology in 10 natural populations across Southern Western Ghats, India was observed to understand the functional rhythm, spatial or temporal differences in the populations and also to understand the reproductive capacity, there by any limiting factors. A total of 97 trees were marked for phenological observations at 10 sites. It was observed that flowering was initiated immediately after flushing and the total period of flowering oscillated between 40 – 120 days. The peak period of anthesis was noticed between 0530 – 0630 hr of the day, which was found to be correlated with temperature and Rh. The total seed output per tree (reproductive capacity) following open pollination was 1,75,545.82 ± 11,934.17, however regeneration potential was very low. L. Speciosa shows annual flowering frequency and comes under the subclass intermediate flowering.