Siqueira et al. 2025 (Article) Tillandsioideae

Stigmatic diversity in Tillandsioideae (Bromeliaceae): a search for homologies

Author(s):—S.F.H. Siqueira, A.F. Costa & K.L.G. De Toni

Publication:—Botanical Journal of the Linnean Society online: boaf086. (2025) — DOI

Abstract:—Tillandsioideae is the subfamily of Bromeliaceae with the most taxonomic and morphological diversity, leading to still-controversial classification in some clades and species groups. Floral morphology, especially of the stigmas, provides relevant data for the circumscription of genera and species. The Bromeliaceae exhibit different stigmatic types with more diversification in Tillandsioideae. This study describes the morphology and ontogeny of the stigmas of 58 species, 47 from Tillandsioideae. The stigmas were examined by scanning electron microscopy. Eleven stigmatic types were identified: simple-erect, simple-truncate, convolute-blade II, III, and IV, lobed-blade, conduplicate-erect, conduplicate-patent, coralliform, lax conduplicate-spiral, and congested, among them the types convolute-blade IV and lobed-blade are herein described for the first time. The ontogeny of the stigmas revealed three ontogenetic sequences with mid-stages homologous to the simple-erect, convolute-blade, and conduplicate-spiral types, giving rise to different homologous morphological types at anthesis. The convolute-blade type showed high diversity, emphasizing the need to consider ontogeny when proposing new types. Morphological differences, which emerge in late stages following different ontogenetic paths, include new stigmatic types, such as lobed stigmatic blades without trichomes and convolute blades with slightly spiralized margins. These results reinforce the importance of ontogeny in the taxonomy and phylogeny of Tillandsioideae.

Keywords:—Bromeliaceae; systematics; ontogeny; taxonomy