The evolutionary origins of flowers and inflorescences.
Amborella trichopoda (Amborellaceae), the putative sister to all other angiosperms. Scanning electron micrographs of female and male flowers. Scale bars = 100μm. Photos: P.Rudall, M.Box.
Research on floral evolution at Kew follows a long tradition that includes the early paleobotanical studies of D.H. Scott and the "New Morphology” of R. Melville. This field was recently revitalised by improved understanding of the phylogenetic relationships of higher plants, augmented by new ideas on the genetic bases for morphological features.
We use targeted comparative ontogenetic studies on a phylogenetically broad range of angiosperms in which the inflorescence–flower boundary is ambiguous, including the monocot order Pandanales, the eudicot family Euphorbiaceae and the early-divergent angiosperm family Hydatellaceae. Some features common to the three case-studies reflect similar developmental constraints, and therefore help to develop testable models of floral construction. We also employ novel techniques such as X-ray tomography (in collaboration with other researchers) to compare extant and fossil flowers.
Key publications 2006-2011
- Rudall P.J. 2006. How many nuclei make an embryo sac in flowering plants? Bioessays 28: 1067–1071.
- Sokoloff, D.D., Rudall, P.J. & Remizowa,M. (2006). Flower-like terminal structures in racemose inflorescences: a tool in morphogenetic and evolutionary research. Journal of Experimental Botany 57: 3517−3530.
- Bateman, R.M., Hilton, & Rudall, P.J. (2006). Morphological and molecular phylogenetic context of the angiosperms: contrasting the “top-down” and “bottom-up” approaches to inferring the likely characteristics of the first flowers. Journal of Experimental Botany 57: 3471–3503.
- Bello, M.A., Hawkins, J.A., & Rudall, P.J. (2007). Floral morphology and development in Quillajaceae and Surianaceae (Fabales), the species-poor relatives of Leguminosae and Polygalaceae. Annals of Botany 100: 1491–1505.
- Prenner, G. & Rudall, P.J. (2007). Comparative ontogeny of the cyathium in Euphorbia and its allies: exploring the organ–flower–inflorescence boundaries. American Journal of Botany 94: 1612–1629.
- Rudall, P.J., Remizowa, M.V., Prenner, G., Prychid, C.A., Tuckett, R. & Sokoloff, D.D. (2009). Non-flowers near the base of extant angiosperms? Spatiotemporal arrangement of organs in reproductive units of Hydatellaceae, and its bearing on the origin of the flower. American Journal of Botany 96: 67–82.
- Smith, S.Y., Collinson, M.E., Rudall, P.J., Simpson, D.A., Stampanoni, M. & Marone, F. (2009). Virtual taphonomy using synchrotron tomographic microscopy reveals cryptic features and internal structure of modern and fossil plants. Proceedings of the National Academy of Sciences 106: 12013–12018.
Project Partners and Collaborators
M. Graça Sajo (UNESP)
Dmitry Sokoloff, Margarita Remizowa (University of Moscow, Russia)