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Data from: Convergent evolution in floral morphology in a plant ring species, the Caribbean Euphorbia tithymaloides

Cite this dataset

Cacho, N. Ivalú; Monteverde-Suárez, Maria José; McIntyre, Patrick J. (2019). Data from: Convergent evolution in floral morphology in a plant ring species, the Caribbean Euphorbia tithymaloides [Dataset]. Dryad.


Premise of the Study: Ring species have long fascinated evolutionary biologists for their potential insights into lineage divergence and speciation across space. Few studies have investigated the potential for convergent or parallel evolution along the diverging fronts of ring species. We investigate a potential case of parallel floral variation in the Caribbean spurge Euphorbia tithymaloides, the only plant system with molecular support as a ring species. The terminal populations of each front, despite being the most divergent, exhibit such similar floral traits that were originally considered each other closest relative. Methods: We evaluate convergence in floral and leaf traits in relation to geography across 95 populations spanning the distribution of E. tithymaloides. We also re-analyze available genetic data (from previous phylogenetic analyses) in an explicitly spatial framework. Key Results: Floral morphology appears to have shifted in a convergent fashion along both geographic fronts of E. tithymaloides, resulting in shorter and more compact inflorescences in Antillean populations compared to the typical elongate ‘slipper-like’ cyathia characteristic of the area of origin. Patterns of spatial genetic variation were more consistent with a two-fronted invasion of the Caribbean than a simpler model of isolation by distance. Conclusions: Floral divergence in E. tithymaloides is consistent with convergent evolution along the two fronts of a ring species. We outline several non-mutually exclusive mechanisms that could be driving patterns in morphology, including shifts toward generalized pollination with reduced reliance on hummingbirds, shifts in floral structure closely matching available hummingbird bill traits, and shifts toward increased selfing. Please be aware that if you ask to have your user record removed, we will retain your name in the records concerning manuscripts for which you were an author, reviewer, or editor. In compliance with data protection regulations, you may request that we remove your personal registration details at any time. (Use the following URL: Please contact the publication office if you have any questions.

Usage notes


northern South America
Central America