Background and aims: The gametophytic phase of ferns has received little study. This study presents the morphology of the gametophytes of five Elaphoglossum species, from spore germination to the adult stage: E. crassipes, E. hybridum, E. sellowianum, E. spathulatum, and E. yungense. M&M: The study was conducted using in vitro cultures of freshly collected spores on a solidified Dyer medium. Observations were made using light and scanning electron microscopes. Results: Spore germination occurs within the first 10 days. Young laminar gametophytes are asymmetric, whereas adult gametophytes are ribbon-shaped, circular, and cordate symmetric or asymmetric. They either bear clavate and papillose hairs. Unisexual gametophytes were recorded in all five species, bisexual gametophytes only in E. hybridum, and vegetative gametophytes bearing propagules exclusively in E. spathulatum; gametangia exhibit the morphology typical of leptosporangiate ferns in the adult stage. Conclusions: Differences were recorded in spore germination time and in gametangia formation, evidencing variation in the developmental pace of the gametophytic phase within the genus. The morphology of adult gametophytes, hair type, sexuality, and formation of vegetative propagules are relevant diagnostic characteristics of the sexual phase of these ferns.
Background and aim: A lichenological study was conducted in the Tati Yup & iacute; Natural Reserve, part of the Alto Paran & aacute; Atlantic Forest in Paraguay, a highly biodiverse yet critically threatened ecoregion. The aim of this study is to provide a taxonomic characterization of the species of the genus Porina in the Tati Yup & iacute; Natural Reserve, contributing to the knowledge of the group's diversity in Paraguay. M&M: Random sampling was carried out in 2019. Specimens were analyzed using standard lichenological techniques, including morphology (light microscopy) and chemistry (spot tests and thin-layer chromatography). Results: The presence of four species is confirmed: Porina internigrans, P. mastoidea, P. nucula, and P. tetracerae. For P. internigrans and P. tetracerae, the first formal records for Paraguay are presented, based on herbarium material. In the case of P. mastoidea and P. nucula, previously cited imprecisely, morphological descriptions based on voucher specimens are provided. All species are documented through detailed descriptions and chemical characterization. Conclusions: The results include formal records of Porina for Paraguay based on herbarium material. These findings indicate that lichen diversity in Paraguay remains underestimated and highlight the importance of taxonomic studies based on morphological and chemical characters.
Background and aims: The aim of this study was to determine whether the passage of Schinus fasciculatus (moradillo) seeds through the avian digestive tract affects their viability, germination capacity, onset and rate of germination, and to assess whether this effect varies according to the disperser in the Espinal Forest. M&M: A total of 243 fecal samples from 31 bird species were analyzed, from which 198 seeds were collected, 108 of them intact. Results: The germination capacity (PG) of dispersed seeds was significantly higher (13.88 %) than that of the control (10.10 %). However, the effect was disperser-specific: Pitangus sulphuratus and Turdus rufiventris significantly increased PG, Elaenia albiceps reduced it, and Columbina picui and Turdus amaurochalinus induced dormancy. The differences observed among species indicate that the impact of gut passage on germination depends on the physiological and ecological traits of each bird. Conclusions: Overall, these findings highlight the importance of conserving local frugivore communities as a key component for the sustainability and resilience of Espinal Forest ecosystems
