Flowering of Dillenia pentagyna. The tree bloomed yesterday morning at CEC BNHS. There wasn't a single leaf. When I was passing under the tree I could hear the buzzing sound of hundreds of honey bees feasting on the nectar and helping in pollination. I went to see the flowers again in the afternoon and the road under the tree was golden yellow with the sprinkle of petals of the tree. All flowers had shed the petals and only few honey bees could be seen on the tree. The flowering was over. Here are three photographs. Another tree had blossomed 18th June 2019. At BNHS Conservation Education Centre (CEC), Goregaon, Mumbai. Dt. 19 June 2019.
Once pollinated, why continue to spend resources to attract pollinators? Many flowers on many plants, once pollinated, make the transition from flower to seed development pretty quickly.
A one-day blooming flowers are well known in mass flowering trees that carry a very high number of flowers and relatively a small number of fruits. This reproductive strategy allows an effective competition among the potential progenies. An avocado tree carries about one million flowers during a flowering season of 4-6 weeks. Each flower opens for 5 hours as a female, close for the night, and opens again on the following day for another 5 hours as a male. So it is receptive for less than a day. Out of the one million flowers on a tree only 2-5% succeed to set, about 40,000 small fruits per tree, and out of these small fruits about 1% only grow for adult fruits. Therefore, a competition for pollination is carried among the female flowers, and a similar competition for visitation happen among the male ones as well. A more severe competition on the tree is in force among the tens thousands of small fruits, which carry combinations of both male and female traits.
Mass flowering trees' flowers are open for only a day to allow as many flowers as possible along the limited blooming season. However, a tree that carries many one-day blooming flowers, which all open simultaneously on the same day looks strange. It is too risky.
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