Abstract:We describe and illustrate Paepalanthus magistrae, a remarkable new species of Eriocaulaceae from Northeastern Brazil. The species is placed into Paepalanthus subsect. Dichocladus by the presence of trimerous flower, elongated dichotomous branched stem, and small rigid leaves. Within the section it may be easily distinguished by its leaves with glabrescent adaxial surface and lanose abaxial surface. As the species is narrowly distributed and known from a few populations, it is considered endangered.
“… Eriocaulaceae Martinov is a monocotyledon family belonging to the Poales (APG IV 2016), which comprises around 1400 species divided into 18 genera ( Giulietti et al 2012 ; Andrino et al 2023 ; Sano et al 2024 ) and two subfamilies: Eriocauloideae Ruhland and Paepalanthoideae Ruhland ( Ruhland 1903 ). It has a pantropical distribution, but an important center of diversity is found in the campos rupestres of east Brazil, especially in the Espinhaço Range (ER), where the family represents around 10% of the diversity of vascular plants, with an endemism rate of 85% ( Costa et al 2008 , 2018 ).…”
Paepalanthus is a diverse genus characteristic of the campos rupestres, a megadiverse vegetation found on mountaintops of mainly quartzitic mountain ranges of central-eastern Brazil. Recent efforts on prospecting the biodiversity of Serra do Padre Ângelo, a small mountain complex in eastern Minas Gerais, yielded several new plant and animal species, highlighting the urgency of conservation actions towards this still unprotected area. Here, we describe yet another new species found in the campos rupestres of these mountains, Paepalanthus magnus, a mountaintop microendemic species morphologically similar to taxa found in the Espinhaço Range, over 200 km distant, a biogeographic pattern shared by several other species. The affinities of the new species are discussed, and we provide illustrations, photographs, and SEM photomicrographs of the seed. We also discuss the conservation status of the species, which is preliminarily assessed as Critically Endangered, reinforcing the urgent need to address the conservation of the unique biodiversity of Serra do Padre Ângelo.
“… Eriocaulaceae Martinov is a monocotyledon family belonging to the Poales (APG IV 2016), which comprises around 1400 species divided into 18 genera ( Giulietti et al 2012 ; Andrino et al 2023 ; Sano et al 2024 ) and two subfamilies: Eriocauloideae Ruhland and Paepalanthoideae Ruhland ( Ruhland 1903 ). It has a pantropical distribution, but an important center of diversity is found in the campos rupestres of east Brazil, especially in the Espinhaço Range (ER), where the family represents around 10% of the diversity of vascular plants, with an endemism rate of 85% ( Costa et al 2008 , 2018 ).…”
Paepalanthus is a diverse genus characteristic of the campos rupestres, a megadiverse vegetation found on mountaintops of mainly quartzitic mountain ranges of central-eastern Brazil. Recent efforts on prospecting the biodiversity of Serra do Padre Ângelo, a small mountain complex in eastern Minas Gerais, yielded several new plant and animal species, highlighting the urgency of conservation actions towards this still unprotected area. Here, we describe yet another new species found in the campos rupestres of these mountains, Paepalanthus magnus, a mountaintop microendemic species morphologically similar to taxa found in the Espinhaço Range, over 200 km distant, a biogeographic pattern shared by several other species. The affinities of the new species are discussed, and we provide illustrations, photographs, and SEM photomicrographs of the seed. We also discuss the conservation status of the species, which is preliminarily assessed as Critically Endangered, reinforcing the urgent need to address the conservation of the unique biodiversity of Serra do Padre Ângelo.
“…Eriocaulaceae is a well-represented monocot family in the Brazilian flora, with approximately 620 species in Brazil (BFG, 2015; Sano et al, 2015). Flowers in Eriocaulaceae are generally trimerous as in most other monocots (Ruhland, 1903; Stützel, 1998).…”
BackgroundFlowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur in Paepalanthus and a few other genera. The floral merism in an evolutionary context, however, is unclear. Paepalanthus encompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative studies of infrageneric groups in Paepalanthus and in Eriocaulaceae are lacking, albeit necessary to establish evolution of characters such as floral merism and their role as putative synapomorphies.MethodsWe studied the floral development and vascularization of eight species of Paepalanthus that belong to distinct clades in which dimery occurs, using light and scanning electron microscopies.ResultsFloral ontogeny in dimerous Paepalanthus shows lateral sepals emerging simultaneously and late-developing petals. The outer whorl of stamens is absent in all flowers examined here. The inner whorl of stamens becomes functional in staminate flowers and is reduced to staminodes in the pistillate ones. In pistillate flowers, vascular bundles reach the staminodes. Ovary vascularization shows ventral bundles in a commissural position reaching the synascidiate portion of the carpels. Three gynoecial patterns are described for the studied species: (1) gynoecium with a short style, two nectariferous branches and two long stigmatic branches, in most species; (2) gynoecium with a long style, two nectariferous branches and two short stigmatic branches, in P. echinoides; and (3) gynoecium with long style, absent nectariferous branches and two short stigmatic branches, in P. scleranthus.DiscussionFloral development of the studied species corroborates the hypothesis that the sepals of dimerous flowers of Paepalanthus correspond to the lateral sepals of trimerous flowers. The position and vascularization of floral parts also show that, during dimery evolution in Paepalanthus, a flower sector comprising the adaxial median sepal, a lateral petal, a lateral stamen and the adaxial median carpel was lost. In the staminate flower, the outer whorl of staminodes, previously reported by different authors, is correctly described as the apical portion of the petals and the pistillodes are reinterpreted as carpellodes. The occurrence of fused stigmatic branches and protected nectariferous carpellodes substantiates a close relationship between P. sect. Conodiscus and P. subg. Thelxinoë. Free stigmatic branches and exposed carpellodes substantiate a close relationship between P. sect. Diphyomene, P. sect. Eriocaulopsis and P. ser. Dimeri. Furthermore, the loss of nectariferous branches may have occurred later than the fusion of stigmatic branches in the clade that groups P. subg. Thelxinoë and P. sect. Conodiscus.
“…7 The Espinhaço Range in southeastern Brazil is the center of diversity of Paepalanthus, and the genus is also quite diverse on the Guiana Shield and, to a lower degree, in central Brazil and within the Atlantic Forest domain. 8 In the context of the need to preserve Eriocaulaceae due to many of these species being endangered and considering the absence of records or studies involving the endophytic fungi-Eriocaulaceae interactions, 9 this work describes the first chemical study of A. brabeji, an endophytic fungus found in the Xylariaceae family, with over 1300 species accommodated in more than 70 genera. 10 The first fungus identified from the leaves of Brabejum stellatifolium belongs to the typical vegetation of South Africa called "fynbos", 11,12 but this fungus was isolated and identified for the very first time in Brazilian vegetation.…”
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