Morphometrical analysis of Ceiba Mill. (Bombacoideae, Malvaceae) pollen: a sacred plant of the Mayan (Mesoamerican) civilisation

Abstract

Ceiba, is a large tree used for ornamental landscaping in tropical regions of the world. It is found in tropical areas, including Mexico, Central America, South America, the Caribbean, West Africa, and Southeast Asia. The present work communicates the detailed pollen morphology of four Ceiba species growing in India including one hybrid, C. speciosa (A.St.-Hil.) Ravenna, C. insignis (Kunth) P. E. Gibbs & Semir, C. x insignis (cross between C. insignis and C. speciosa) and C. pentandra (L.) Gaertn., using Field Emission Scanning Electron Microscope (FESEM), Confocal Laser Scanning Microscope (CLSM) and Light Microscope (LM) to highlight the taxonomic characterization of these species and document finer morphological details to correlate them with other Ceiba spp., growing around the world. Pollen grain is 4-5-colporate, brevicolpate; sub-oblate to prolate-spheroidal to sub-prolate; sexine reticulate (muri provided with scattered spinuloid excrescences, lumina reticolumellate) and mostly thicker than nexine. The multivariate principal component analysis (PCA) was applied on Ceiba and Bombax ceiba to numerical data obtained from pollen morphometry which clearly revealed a significant variation between different genus and species. A pollen key, based on these micromorphological data (especially pollen aperture and size of muri), is also presented for the Ceiba and B. ceiba. The study provides an analogue for precise identification of Ceiba pollen grains recovered in Quaternary and pre-Quaternary sedimentary deposits in India and other tropical and subtropical regions of the world. Besides, pollen preservation, evolutionary trend and palaeoecology are the other important implications of this study.

Keywords:

• Ceiba
• bombax
• pollen morphology
• sacred
• ornamental
• Lucknow
• India

Acknowledgements

Thanks are due to Dr. Subodh Kumar during FESEM studies and Mr. Jagdeesh for chemical processing. I am gratified to Mrs. Tusha Tripathi and Dr. Biswajeet Thakur for their kind help.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We are highly thankful to Prof. Sunil Bajpai, Director, BSIP, Lucknow for his encouragement and permission for the collaborative research (No. BSIP/IV/SA/Collaboration/2015-16/L-2113) and publication (No. BSIP/RDCC/Publication no. 81/2017-18). Thanks are due to Dr. Subodh Kumar during FESEM studies and Mr. Jagdeesh for chemical processing. I am gratified to Mrs. Tusha Tripathi and Dr. Biswajeet Thakur for their kind help.

We are highly thankful to Prof. Sunil Bajpai, Director, BSIP, Lucknow for his encouragement and permission for the collaborative research (No. BSIP/IV/SA/Collaboration/2015-16/L-2113) and publication (No. BSIP/RDCC/Publication no. 81/2017-18).

Notes on contributors

Swati Tripathi

SWATI TRIPATHI is currently working as a Scientist-C in the Quaternary Laboratory of the Birbal Sahni Institute of Palaeosciences, Lucknow. Her research interests include quaternary vegetation and climate change through pollen and non-pollen palynomorphs. She is an associate of the prestigious Indian Academy of Sciences, Bangalore. She has 32 research papers published in peer reviewed journals.

Anjum Farooqui

ANJUM FAROOQUI is affiliated to Quaternary Palynology Laboratory, Birbal Sahni Institute of Palaeosciences. She has a research experience of about 25 years in the field of Quaternary climate and vegetation using pollen/spores, non-pollen forms such as phytolith and testate amoebae. She has to her credit about 90 publications in National and International Journals. She has extensive field experience in coastal areas and Western Ghats of India.

VeeruKant Singh

VEERU KANT SINGH is presently working as a Scientist-D at the Birbal Sahni Institute of Palaeosciences, Lucknow, India. He is currently engaged in palaeobiological studies of Proterozoic sediments of the Indian subcontinent (Central India) to understand the Evolution and diversification of Proterozoic eukaryotes. He is actively engaged in working and functioning of the Confocal Laser Scanning Microscope (CLSM) and Laser-Raman Spectroscopy (LRS) instruments.

Shilpi Singh

SHILPI SINGH, Phd scholar in botany at the National Botanical Research Institute, Lucknow. Her Ph.D. work on the morphological, palynology and molecular studied on the Bougainvillea species and varieties. She is currently engage with the pharmacognosy studies of medicinal plants. Her field of specialiszation includes taxonomical studies of ornamental climbers, shrubs, trees etc.

Rup Kumar Roy

RUP KUMAR ROY is currently working as a consultant in the CSIR-National Botanical Research Institute, Lucknow. After PhD in Horticulture, he was appointed as a Scientist in the Botanic Garden, National Botanical Research Institute, Lucknow. He received several awards in the floriculture field. He has about 90 research publications and 15 books to his credit.