Plant Systematics and Evolution Supplementum 6

Transcription

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2 Plant Systematics and Evolution Supplementum 6

3 P. F. Yeo Secondary Pollen Presentation F o TIn, Function and Evolution Springer-Verlag Wien GmbH

4 Dr. P. F. YEO University of Botanic Garden Cambridge, United Kingdom This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machines or similar means, and storage in data banks Springer-Verlag Wien Originally published by Springer-Verlag Wien New York in 1993 Softcover reprint ofthe hardcover Ist edition 1993 Typesetting: Thomson Press (India) Ltd., New Delhi, With 55 Figures ISSN ISBN ISBN (ebook) DOI /

5 Preface Secondary pollen presentation is the presentation of pollen either on floral structures other than the anther-sacs (thecae) in which it is produced or by special mechanisms of expulsion involving contact of the pollen with other floral parts. This intriguing subject has until now remained largely unexplored and few botanists seem to be aware of it. This is in spite of the fact that secondary pollen presentation is virtually universal in the Asteraceae (Compositae), the largest family of flowering plants, and common in the Leguminosae, a family including many crops, for which successful pollination is of great economic importance. Secondary pollen presentation is universal in other major families such as the Campanulaceae and Lobeliaceae. It is also prevalent in the extraordinarily interesting southern hemisphere family Proteaceae and the very large tropical family Rubiaceae. Information on secondary pollen presentation is scattered in the literature of floral biology; I have now brought it together for the first time and added some of my own. This has made it possible to consider the adaptive significance of the different forms of secondary pollen presentation and the patterns of its occurrence in relation to classification and evolution, affording a basis for comparative study. We need to know a great deal more about secondary pollen presentation before we can fully understand it, and I give suggestions for further research (information is incomplete for almost all the plants dealt with in this book). Enquiries are needed at varied levels on topics ranging from structure to the mechanics of pollen delivery, and from pollinator behaviour to pollen dispensing, pollen transport, pollination success and pollen/ovule ratios. These are all fields of current interest and there are possibilities here for project work in schools and universities. I hope the book will also provide useful background for morphologists and taxonomists, encouraging more of them to follow the current trend of considering function when they are describing structures. Above all it is intended to serve as a source-book for floral biologists and pollination ecologists. I began gathering information for this review in In 1987, when I had written about half of the first draft, I learned that Dr. CHRISTIAN WESTERKAMP had begun a similar project. As my work was considerably more advanced than his he generously put his ideas and a large bibliography at my disposal. He and all others who have helped in any way with the preparation of this work are gratefully thanked; many have gone to considerable trouble. The following helped with general discussion and/or comments on the introduction and the discussion section: S. A. CORBET, A. DAFNI, A. J. LACK, CHR. WESTERKAMP. Those who commented on and supplied information for particular families are D. BRIDSON (Rubiaceae), B. G. COLLINS (M yrtaceae, Proteaceae), H. A. FORD

6 VI Preface (Proteaceae), P. E. GIBBS (Papaveraceae, Vochysiaceae), E. HOLM (Myrtaceae), Y. HESLOP-HARRISON (pollen of Asteridae), S. D. HOPPER (Proteaceae), W. J. KRESS (Cannaceae, Marantaceae), L. A. S. JOHNSON (Proteaceae), D. G. LLOYD (Lobeliaceae), D. MACFARLAND (Proteaceae), R. MAKINSON (Proteaceae), R. M. POLHILL (Leguminosae), T. J. ROSATTI (Apocynaceae, Campanulaceae), C. H. STIRTON (Leguminosae), S. STUMPF (Goodeniaceae, Lobeliaceae), E.-M. THIELE (Asteraceae), V. TURNER (Proteaceae), B. VERDCOURT (Rubiaceae), P. S. WESTON (Proteaceae), F. WHITE (Meliaceae), CHR. WESTERKAMP (Liliaceae and literature references for many families). Permission to use illustrations has been received from the following (in many cases original drawings have been lent): for Fig. 1, Der Palmengarten, Stadt Frankfurt am Main, and Dr CHR. WESTERKAMP, for Fig. 9. Eucnide urens, The Journal of the Arnold Arboretum; for Fig. 10. Acrotriche serrulata, The Annals of Botany Company (Harcourt Brace Jovanovich) and Dr C. A. MCCONCHIE; for Fig. 11. Stylosanthes gracilis, M. R. PEREIRA-NoRONHA; for Fig. 14. Bruguiera gymnorhiza (from the Journal of South African Botany), The South African Association of Botanists and 1. E. BARTON (nee DAVEY); for Fig. 15. Darwinia vestita, Fig. 16. Darwinia macrostegia and D. citriodora, Fig. 17. Verticordia huegelii and V. habrantha, Fig. 18. V. grandis, Fig. 19. Actinodium cunninghamii and Chamelaucium uncinatum, Fig. 22. Grevillea eriostachya, Fig. 23. Grevilleafasciculata, Fig. 24. Banksia coccinea and Fig. 25. B. prionotes and B. dryandroides, E. HOLM; for Fig. 28. Polygala vauthieri and P. monticola var. brizoides, Springer-Verlag and N. B. M. BRANTJES; for Fig. 29. N erium oleander, Prof. dr. L. 1. G. VAN DER MAESEN (editorial board, Wageningen Agricultural University Papers) and Ir. FRANK PAGEN; for Fig. 30. Nerium oleander, The Linnean Society of London and J. HERRERA; for Fig. 31. Stephanostema stenocarpum, the Department of Plant Taxonomy, Agricultural University, Wageningen, by courtesy of Prof. dr. L. 1. G. VAN DER MAESEN; for Fig. 36. Wahlenbergia consimilis, the Bentham-Moxon Trustees (Royal Botanic Gardens, Kew) and E. M. STONES; for Fig. 38. Lobelia cardindlis, S. STUMPF; for Fig. 39. [sotoma petraea, the editor and publisher of Acta Botanica Neerlandica and N. B. M. BRANTJES; for Fig. 40. [sotoma axillaris, Fig. 41. Scaevola crassifolia and Fig. 43. Selliera radicans, S. STUMPF; for Fig. 42. Scaevola thesioides var.filifolia, Fig. 44. Dampiera cuneata and Fig. 45. Lechenaultia tubiflora, E. HOLM; for Fig. 48. Asteraceae, J. Cramer (Gebrtider Borntraeger) and Dr E.-M. THIELE. Cambridge, 1992 P. F. Yeo

7 Contents Chapter 1. Introduction and explanations 1. Definition and scope 2. Sources of information Terminology Standardized summaries of secondary pollen presentation Chapter 2. Descriptions of secondary pollen presentation M agnoliidae M agnoliales M yristicaceae Papaverales Papaveraceae (s. 1.) Dilleniidae Malvales Sterculiaceae Violales Loasaceae.. Ericales Epacridaceae Rosidae Fabales Leguminosae Myrtales Rhizophoraceae Myrtaceae Proteales Proteaceae Sapindales Meliaceae RajJlesiales RajJlesiaceae. Polygalales Vochysiaceae Polygalaceae Asteridae Gentianales Apocynaceae

8 VIII Contents Campanulales Campanulaceae Cyphiaceae Lobeliaceae. Goodeniaceae Rubiales Rubiaceae Asterales Asteraceae.... Subfam. Cichorioideae Subfam. Asteroideae Alismatidae H ydrocharitales... Hydrocharitaceae Commenlinidae Commelinales Xyridaceae Zingiberales Cannaceae. M arantaceae Liliidae Liliales Liliaceae.... Addendum: Dipsacales, Calyceraceae Chapter 3. General discussion 1. Preamble Functions of secondary pollen presentation 3. Evidence for pollen-saving 4. Ways of preventing selfing Stigmatic membranes... ~.. 6. Pollen longevity and secondary pollen presentation 7. Pollen flowers Adhesives Structures involved in secondary pollen presentation in relation to taxonomic position Type of pollen presentation in relation to taxonomic position 11. Evolution of secondary pollen presentation: constraint and canalization , Speculations on courses of evolution Chapter 4. Summary and conclusions... References Appendix 1. Possibilities for future research Appendix 2. Coded summaries tabulated Index of plant names