Pollination ecology of Clerodendrum inerme (L.) Gaertn. (Lamiaceae) in Coringa mangrove ecosystem, Andhra Pradesh, India

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A.J. Solomon Raju
Rajendra Kumar


Clerodendrum inerme (L.) Gaertn. (Lamiaceae) is bisexual, self-compatible and has a vector-dependent mixed breeding system.  They are dichogamous and herkogamous; the day 1 flowers are staminate while the day 2 and 3 flowers are pistillate.  The plant blooms in the evening, possesses a white long corolla with a hairy interior to exclude other insects and strong fragrance are adaptations for pollination by the hawk-moth Macroglossum gyrans.  The 2nd and 3rd day flowers are nectar-rich and attract hawk-moths during the dawn and dusk hours.  The plant is also visited by bees and butterflies.  The bees Xylocopa and Anthophora are primary nectar robbers which collect nectar without effecting pollination.  In C. inerme, three forms of flowers can be distinguished based on the position of sex organs.  The first form is characterized by elongated stamens and a style which occur in close proximity to each other just after anthesis facilitating contact between the stamens and stigma.  The second form is characterized by the scattered position of stamens and style.  In the third form, the stamens are fully extended while the style is curved away from them, either to the left or to the right; subsequently the stamens curl inward and the style elongates. Interestingly, the three flower forms can be found within a cyme also.  These forms of flowers with strong protandry prevent autonomous selfing but not geitonogamy.  The fruit is a capsule and breaks open to disperse nutlets.  Birds such as Acridotheres tristis, Corvus splendens, Corvus macrorhynchos and Turdoides caudatus disperse nutlets during the early winter season. Seeds germinate in June and seedlings grow gradually to produce new plants.


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Author Biographies

A.J. Solomon Raju, Department of Environmental Sciences, Andhra University, Visakhapatnam, Andhra Pradesh 530003, India

Dr. Aluri Jacob Solomon Raju is a Professor of Environmental Sciences in Andhra University, Visakhapatnam, India. He was the Head of the Department during 2009-2012. He was the Visiting Professor of University of Colima, Mexico. He was a Post-Doctoral Research Fellow at the University of Akron, USA for a period of two years. He has conducted extensive field work in Olympic Mountains, Colorado Rocky Mountains, Siskiyu Mountains, Yosemite National Park, Yellostone National Park and Grand Teton Mountains in connection with reproductive biology of an arctic-alpine genus Pedicularis and its conservation and management aspects. Further, he has also conducted field research in Mexico. He has published more than 300 research papers, participated and presented scores of research papers at more than 50 national and more than 30 International conferences held in India and abroad. He visited USA, Canada, UK, Brazil, Paraguay, Italy, Mexico, France, Germany, China, Hong Kong, Thailand, Malaysia, Ethiopia and Tanzania. In recognition of his superior record of scholarship, he was awarded Distinguished Achievement Award by the University of Akron, USA. He is also the recipient of Best Research Award and Dr. Sarvepalli Radhakrishnan Best Academician Award of Andhra University, Loyola Environmental Award from Loyola College, Chennai and Andhra Pradesh Scientist Award from Andhra Pradesh Council of Science & Technology, Govt. of Andhra Pradesh. He successfully completed a number of major research projects on the Eastern Ghats Forests funded by ICAR, UGC, DST, CSIR, DBT and MoEF. He was the Expert member of the Ministry of Environment and Forests, Govt. of India in sanctioning the research projects. He has also worked on biodiesel plants such as Pongamia and Jatropha and work on these plants laid foundation for others to initiate work in commercial lines. He has also published ten books on various subjects published by national and international publishers. Twenty Ph.Ds and 10 M.Phils were awarded under his guidance. Further, he is currently serving as a resource person for All India Radio, TV Channels, Consultant for issues relating to conservation biology and environment. Further, he is currently operating All India Coordinated Research Project on the endangered species of Eastern Ghats funded by MoEF, on reproductive ecology of Coringa Mangrove Forest funded by MoEF and on reproductive ecology of rare plants of Eastern Ghats funded by CSIR, New Delhi. He is an expert-cum-reviewer for scores of scientific journals published by Elsevier, Springer publishers, Indian Publishers, US Publishers and African Publishers. He is the Chief Editor of Advances in Pollen-Spore Research and Guest Editor of Journal of Palynology.


Rajendra Kumar, Ministry of Environment, Forest and Climate Change, Indira Paryavaran Bhavan, Jor bagh Road, New Delhi 110003, India

He is currently working as Research Officer in the Ministry of Environment, Forest and Climate Change, Government of India, New Delhi.  He has published six research papers.


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