Almeida et al. 2026c (Article) palynology

Morphology and anatomy of pollen grains of seven species of Pitcairnioideae (Bromeliaceae) using various microscopy techniques (fluorescence, light and scanning electron microscopy).

Author(s):—P.S. Almeida, M.C.N.d. Silva, S.A. Kuhn, C.B.F. Mendonça, J.E.A. Mariath & V. Gonçalves-Esteves

Publication:—Palynology : 1-18. (2026) — DOI

Abstract:—Pitcairnioideae, a monophyletic subfamily within Bromeliaceae, comprises five genera. Although the subfamily is considered stenopalynous, in-depth analyses of its pollen grains and little-studied structures, such as the intine, may contribute to more accurate descriptions and help elucidate characters that clarify its circumscription. The general objective of this study was to describe the pollen types and characteristics of the sporoderm strata, including the exine and intine, across all genera of Pitcairnioideae. Specimens were analyzed using anatomical methods (light and fluorescence microscopy), acetolytic treatment, and scanning electron microscopy. Pollen grains of the subfamily are dispersed in monads, have an elliptical amb and oblate shape, and possess a sulcus of the simple type. In Pitcairnia artrorubens, the sulcus is of the insulae type. The ornamentation is reticulate, except in Fosterella lilliputiana, which has microreticulate ornamentation, and simplicolumellate, except in Encholirium agavoides, which exhibits duplicolumellate regions. The intine is stratified into three layers in the apertural region and, in some species, shows streaked structures. Although the subfamily can be described as stenopalynous, a more refined analysis revealed specific variations in pollen characters that may prove useful for applied studies.

Keywords:—Bromeliaceae, exine, intine, palynology, Pitcairnioideae.