Importance of palynology in the taxonomy of Piptolepis Sch.Bip. (Asteraceae: Lychnophorinae), a genus endemic to Brazil

Abstract

Lychnophorinae comprises 19 genera and 117 species. Its representatives are found mostly in the rocky grasslands ("campos rupestres") of Minas Gerais, Bahia, and Goiás States, Brazil. This study presents a palynological investigation of 10 species belonging to the genus Piptolepis, endemic to the rocky grasslands of the Espinhaço Mountains, in Minas Gerais State. The plant material used in this investigation was obtained from specimens deposited in Brazilian herbaria. Pollen grains were processed by the acetolysis method, measured, described, and photomicrographed in light microscopy and scanning electron microscopy. Morphological observations revealed Piptolepis pollen to be large, prolate spheroidal in most species, 3-colporate, ectoapertures long, sexine subechinolophate or sublophate. Endoapertures vary from almost circular, lalongate or lalongate, with a median constriction observed only in three species. Three types of spines were identifi ed: prostrate and disorganized, elongated and narrow, and conical, erect, apex acute in the other species. This fi rst palynological study of Piptolepis species allowed the separation of representatives of the genus using pollen keys. The most signifi cant characters were pollen shape, ornamentation, endoaperture, and presence of median constriction in the endoaperture. The fi ndings presented here do not support the infrageneric classifi cation of Piptolepis, as pollen characters were not unique to any section.

Palynotaxonomy of species of Dendrophorbium (Asteraceae: Senecioneae) occurring in Brazil

“…and, less commonly, of other recent and fossil palynomorphs. In Brazil, important contributions to the palynology of Asteraceae were made by Salgado-Labouriau (1973); Melhem et al (2003); Mendonça and Gonçalves-Esteves (2000); Mendonça et al (2002, 2007a, 2007b, 2009, 2010); Cancelli et al (2005, 2010); Magenta et al 2010; Souza et al (2016); Souza-Souza et al (2016); Siniscalchi et al (2017); Moreira et al (2018); Soares et al (2020) and Souza-Souza et al (2021, 2022). This study aimed to morphologically characterize the pollen grains of the 13 species of Dendrophorbium that occur in Brazil, of which 11 were described palynologically, for the first time.…”

Palynotaxonomy of Calea sect. Meyeria (Asteraceae: Neurolaeneae)

“…Numerous palynological studies have been conducted on Asteraceae (Gonçalves-Esteves 1976, 1977a, 1977b; Gonçalves-Esteves and Esteves 1986, 1988a, 1989a, 1989b; Mendonça et al 2002; Cancelli et al 2005, 2010; Magenta et al 2010; Moreira et al 2019; Reshmi and Rajalakshmi 2019; Ulukuş and Tugay 2020; Marques et al 2021; Souza-Souza et al 2021, 2022; Tellería et al 2023). However, there are no specific papers describing the palynology of the tribe Neurolaeneae, only studies focused on Asteraceae that evaluated the pollen of some Neurolaeneae species: Calea species (e.g.…”

“…However, there are no specific papers describing the palynology of the tribe Neurolaeneae, only studies focused on Asteraceae that evaluated the pollen of some Neurolaeneae species: Calea species (e.g. Roubik and Moreno 1991; Melhem et al 2003; Cancelli et al 2010; Stanski et al 2014; Souza-Souza et al 2022) and Enydra Lour. species (Perveen 1999; Cancelli et al 2010).…”

Pollen morphology: a source of information for taxonomic studies within Campomanesia (Myrtaceae)

“…Pollen morphology is widely used to clarify taxonomic issues among angiosperms (e.g. Christensen 1986; Carrijo et al 2013; Silva-Fourny et al 2018; Oliveira et al 2019; Ragho 2020; Araújo et al 2021; Souza-Souza et al 2022) and has proven informative for delimiting species of Psidium L. (Tuler et al 2017), another genus of Pimentinae within Myrtaceae. However, few species of Campomanesia have had their pollen grain morphology described in the literature (Barth and Barbosa 1972; Thornhill et al 2012d; Corrêa et al 2018).…”