Annals of Botany

Floral elaiophore structure in the Gomesa and Oncidium clades

Floral elaiophore structure in the <i>Gomesa</i> and <i>Oncidium</i> clades
Floral elaiophore structure in the Gomesa and Oncidium clades

Recent molecular approaches have resulted in the re-circumscription of Gomesa and Oncidium (Orchidaceae; Oncidiinae), together with their respective clades. Stpiczyńska et al. compare the anatomical organization of the floral elaiophore (oil gland) of a further four species of Oncidiinae (two species from each clade), and find that in terms of location, morphology, anatomy and ultrastructure, the floral elaiophores of both Gomesa and Oncidium species are very similar, and distinction between these genera is not possible based on these features alone. Furthermore, many of these elaiophore characters are shared with representatives of other clades of Oncidiinae, including the Ornithocephalus clade. Consequently, elaiophores are considered homoplasious and of limited value in investigating the phylogeny of this subtribe.