Santos et al. 2025 (Article) Tillandsia, Brazil, Morphometry

Morphometric characterization of three sympatric species of Tillandsia (Bromeliaceae) occurring in rocky outcrops in Southern Brazil

Author(s):—E.C.C. dos Santos, R.C. Tardivo & F.R. da Maia

Publication:—Plant Systematics and Evolution 311(5): 31. (2025) — DOI

Abstract:—Morphometric studies, including multivariate analyses, have proven to be a valuable tool for estimating biodiversity, effectively elucidating morphological characteristics useful in species identification. In this study, we investigated morphological variation in three sympatric species of the genus Tillandsia, in an area of sandstone outcrops in the Southern region of Brazil. We evaluated 26 vegetative and reproductive morphological attributes using a multivariate approach that employed principal component analysis, principal coordinates analysis, and cluster analysis. Additionally, we recognized and classified the micromorphology of pollen grains and the stigma presented by each species. As a result, we observed that a total of 11 morphological attributes related to leaf shape, length, and width; inflorescence height, type, and number of flowers; sepal, petal, and filament length, better explained the ordination in the principal component analysis, with?absolute? loading factors exceeding 0.25. Principal coordinates analysis grouped individuals that presented morphological characters with similar mean sizes. In the cluster analysis, four groups were formed, with individuals of each species grouped and a group of specimens with contrasting morphology grouped separately. Our results support the morphological pattern described for the three species and reveal individuals with intermediate morphological characteristics between the species T. crocata and T. streptocarpa. We emphasize that the species and study area explored in this work may be promising models for future investigations into evolutionary processes in Neotropical species.

Keywords:—Hybridization · Plant morphology · Species delimitation · Taxonomy · Tillandsioideae