Abstract Based on the review of specimens of the genus Bulbothrix s. lat. supported by morphological and chemical evidence, Bulbothrix buapana is described as a new species collected from a tropical dry forest in Oaxaca, Mexico. It differs from other species of Bulbothrix by having coronate apothecia, the presence of ciliate bulbs all over the upper cortex including the amphithecia, and by containing gyrophoric acid as the main medullary substance. Additionally, B. bulbillosa is reported for the first time in North America, this species also characterized by having ciliate bulbs over the upper cortex, but being isidiate, and by the presence of gyrophoric acid in the medulla. Furthermore, B. fungicola and B. tabacina are newly recorded for the state of Oaxaca, B. isidiza for the state of Veracruz, B. subdissecta for the state of Puebla, and B. ventricosa for the states of Morelos and Oaxaca. A thorough revision of Bulbothrix species is proposed, emphasising the correct identification of ciliate bulbs via the diaphanization procedure and the microcrystallization technique for confirming secondary metabolites. A taxonomic key for species of Bulbothrix s. lat. reported in Mexico is provided.
Fungi are obligate heterotrophs and possess a diverse suite of molecular tools for accessing and processing exogenous carbon. In lichenized fungi, the transfer of photosynthate from photobiont to mycobiont is central to carbohydrate economy; however, major differences in total carbon metabolism are expected to exist between components of the holobiont, that is photoautotrophy in the photobiont versus heterotrophy in the mycobiont and associated microbiota. As well as the nutritional role of sugar monomers, fungi and algae also modify polysaccharide polymers as part of their core cellular processes, for example maintaining cell wall structure (Yoshimi et al . 2016; Fuertes-Rabanal et al . 2025) and processing storage compounds (Wilson et al . 2010), while associated microbiota can be involved in scavenging, recycling (Sigurbjörnsdóttir et al . 2016) or an as-yet undetermined role in the lichen symbiosis (Hawksworth & Grube 2020).
Abstract Lichens are multispecies consortia that visually and semantically masquerade as an ‘organism’, but beneath this illusion lies a fundamental challenge: how do we identify an ‘individual’ for our research? Our aim here is to offer a guide to some of the primary perspectives on individuality as they might apply to lichen symbioses, with an emphasis on the advantages, limitations and best use contexts for each. We introduce three perspectives of individuality that are relevant to the study of lichen symbioses: morphological, physiological and evolutionary individuality. By describing how each framework applies to lichen symbioses, we aim to clarify how individuality is realized in practice, and why these distinctions matter, not just for philosophical debates, but for empirical questions about diversity, biology and evolution. The goal is to emphasize why these different perspectives are relevant to our current research applications in lichenology, and how engagement with these ideas can challenge our current understanding of the symbiosis in constructive ways.
We studied the rarely occurring pycnidial conidiomata in three species of the genus Peltigera using electron microscopy (SEM and TEM). Pycnidia are marginal and half-immersed, having unilocular cavities with double-layered walls and slit-shaped ostioles. The conidiophores are composed of sterile basal and very few axial cells, supporting elongated conidiogenous cells. The conidia are produced at their apices by leaving behind phialidic collarettes either at the same level or in a proliferating manner, extending the conidiogenous cells. The study of the ontogeny of the pycnidial conidiomata demonstrates the origin and the gradual development of the characteristic anatomical structures, such as the wall layers, the bursting ostiole, and the non-chambered cavity, which is completely lined by the conidia-forming elements. The combination of these morpho-anatomical details is unique and hence accepted here as 'Peltigera-type', in addition to previously recognized pycnidia types (Vobis 1980).
