Manhaes et al. 2025 (Article) Stigmatodon, Inselbergs, Brazil

Morphological and Genetic Evidence for the Stigmatodon goniorachis Complex (Tillandsioideae, Bromeliaceae) Reveals a New Species on Inselbergs in the Brazilian Atlantic Forest

Author(s):—V.d.C. Manhães, D.R. Couto, F. Salgueiro & A.F.da Costa

Publication:—Systematic Botany 49(4): 673-694. (2025) — DOI

Abstract:—This study evaluated the morphological variation and genetic structure of seven natural populations of the Stigmatodon goniorachis complex (Bromeliaceae) endemic to vertical faces of inselbergs in the Brazilian Atlantic Forest. A cluster analysis and principal component analysis (PCA) corroborated the existence of four clearly separated species, S. brassicoides, S. costae, S. francae, and S. goniorachis, and unveiled two distinct morphological groups in the S. goniorachis populations. The main components of variation revealed by PCA analysis were: inflorescence peduncle diameter, floral bract length, and hypanthium length. Bayesian population structure analysis based on nuclear microsatellites performed on 145 individuals from six populations initially identified as S. costae, S. francae, and S. goniorachis revealed four genetic clusters (k = 4), two of which consisted of specimens initially identified as S. goniorachis. This result was supported by other genetic analyses including AMOVA, population pairwise genetic distances, and UPGMA analysis. Both morphological and genetic analyses indicated two distinct groups among the four populations initially identified as S. goniorachis, which led to the recognition of a new species described here, Stigmatodon carioca. This new species is morphologically distinct, particularly in the distribution of leaf trichomes and the position of the leaf blade, which occurs in the revolute form. Besides the description of the new species, we present a comparative study that allows the morphological differentiation of the five species.

Keywords:—Genetic diversity, microsatellites, morphometry, multivariate analysis, rock outcrops.

Published names (1):

Stigmatodon carioca