Floral ontogeny in Polygalaceae and its bearing on the homologies of keeled flowers in Fabales

Bello, M. A., Hawkins, J. A. ORCID: https://orcid.org/0000-0002-9048-8016 and Rudall, P. J. (2010) Floral ontogeny in Polygalaceae and its bearing on the homologies of keeled flowers in Fabales. International Journal of Plant Sciences, 171 (5). pp. 482-498. ISSN 1058-5893 doi: 10.1086/651945

Abstract/Summary

Keeled flowers are characteristic of many species of Polygalaceae (tribe Polygaleae), in which there is often a distinctive crest located at the abaxial petal. This study of floral ontogeny across the entire family highlights potential suites of characters that relate to the evolution of keeled and crested flowers. One character suite encompasses interconnected transformations of the lateral perianth organs acting as an evolutionary module: bracteoles, lateral sepals (with delayed initiation and petaloid appearance), and lateral petals (suppressed or lost). The plastochron between initiation of the lateral sepals and that of the other sepals is relatively long in the tribe Polygaleae, in which the calyx is usually heteromorphic. By contrast, in the petal whorl, the difference between a zygomorphic and an actinomorphic corolla involves organ suppression rather than heterochrony. Four primary androecial patterns are identified in the family, and the gynoecium ranges between syncarpous‐bicarpellate and multicarpellate. Stigma diversity is based on two primary morphological types: one in which the papillate stigmatic surfaces lie close together, the other in which they are physically separated. The floral ontogeny of Polygalaceae is considered alongside comparative data available for other members of the order Fabales, and hypotheses to account for the similarities and differences between keeled flowers are discussed.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/18410
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
Uncontrolled Keywords	crest; Fabales; homology; keeled flowers; module; Polygalaceae
Publisher	University of Chicago Press
Download/View statistics	View download statistics for this item