Diversity and evolution of floral structure among early diverging lineages in the Ericales

Author(s)
Jürg Schönenberger, Maria von Balthazar, Kenneth Sytsma
Abstract

This is a combination of review and original data on floral structure and diversity in the two earliest diverging lineages of the Ericales, i.e. the balsaminoids, comprising Balsaminaceae, Marcgraviaceae and Tetrameristaceae, and the polemonioids, comprising Fouquieriaceae and Polemoniaceae. Each clade is strongly supported in molecular studies, while structural synapomorphies have largely been lacking. For the balsaminoid families, we compare floral morphology, anatomy and histology among selected taxa and find that the entire clade is strongly supported by the shared presence of nectariferous tissue in the floral periphery, thread-like structures on anthers, truncate stigmas, secretion in the ovary, as well as mucilage cells, raphides and tannins in floral tissues. A possible sister group relationship between Balsaminaceae and Tetrameristaceae is supported by the shared presence of post-genital fusion of filaments and ovary and a star-shaped stylar canal. For polemonioids, we document unexpected diversity of floral features in Polemoniaceae, partly providing structural links to Fouquieriaceae. Features include cochlear and quincuncial corolla aestivation, connective protrusions, ventrifixed anthers and nectariferous tissue in the base of the ovary. In addition, we outline future directions for research on floral structure in the Ericales and briefly discuss the general importance of structural studies for our understanding of plant phylogeny and evolution.

Organisation(s)
External organisation(s)
University of Wisconsin, Madison
Journal
Philosophical Transactions of the Royal Society of London. Biological Sciences
Volume
365
Pages
437-448
No. of pages
12
ISSN
0962-8436
DOI
https://doi.org/10.1098/rstb.2009.0247
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
106001 General biology
Portal url
https://ucris.univie.ac.at/portal/en/publications/diversity-and-evolution-of-floral-structure-among-early-diverging-lineages-in-the-ericales(53b3cc4d-5ed2-4692-88d6-6b209b2ed53c).html