From the Guiana Highlands to the Brazilian Atlantic Rain Forest: four new species of Selaginella (Selaginellaceae – Lycopodiophyta: S. agioneuma, S. magnafornensis, S. ventricosa, and S. zartmanii)

We describe four new species in the genus Selaginella (i.e., S. agioneuma, S. magnafornensis, S. ventricosa, and S. zartmanii) from Brazil, all presently classified in subg. Stachygynandrum. For each of the new taxa we discuss taxonomic affinities and provide information on habitat, distribution, and conservation status. In addition, line drawings and scanning electron microscope (SEM) images of stems sections, leaves, and spores (when present) are included. Selaginella agioneuma and S. magnafornensis are from the State of Espíritu Santo where they inhabit premontane to montane Atlantic rain forests in the Reserva Biológica Augusto Ruschi and Parque Estadual Forno Grande, respectively. Selaginella ventricosa was collected in upper montane forests at Parque Nacional Serra da Mocidade, State of Roraima and S. zartmanii in premontane Amazon rain forests on upper Rio Negro at Mpio. São Gabriel da Cachoeira, Amazonas State in both Serra Curicuriari and the Morro dos Seis Lagos Biological Reserve

Seven new species of Selaginella subg. Stachygynandrum (Selaginellaceae) from Brazil and new synonyms for the genus

We describe seven new species of Selaginella subg. Stachygynandrum (Selaginella alstonii, Selaginella blepharodella, Selaginella crinita, Selaginella mucronata, Selaginella mucugensis, Selaginella saltuicola, and Selaginella sematophylla) from Brazil and discuss their possible affinities and conservation status. Scanning electron micrographs of stem sections, leaves, and spores are provided to illustrate the new taxa. In Selaginella alstonii and Selaginella saltuicola vegetative growth from strobilus tips is reported and discussed. Four of the new species are from the Espinhaço Mountain Range associated with Campos Rupestres (montane savannah/rocky fields) vegetation. Three of these (i.e., Selaginella blepharodella, Selaginella crinita, and Selaginella mucugensis) were collected in the northern part of the range in Chapada Diamantina, state of Bahia, while Selaginella alstonii is from the southern part of the range in the state of Minas Gerais. Selaginella mucronata is found in Atlantic Rainforest vegetation in the state of Espírito Santo, whereas Selaginella saltuicola inhabits Cerrado (tropical savannah) vegetation in the state of Mato Grosso. Selaginella sematophylla is the most widely distributed of the new species and was collected in Espírito Santo, Minas Gerais, and Rio de Janeiro states in Campos Rupestres and Atlantic Rainforest vegetation. Selaginella alstonii occurs in rocky caves, Selaginella blepharodella, Selaginella crinita, Selaginella mucugensis, and Selaginella sematophylla seem adapted to seasonally dry places, living on sandy or humid soils, Selaginella mucronata occupies humid, forest understory, and Selaginella saltuicola is adapted to wet places associated with rocks or logs in waterfalls. Of the seven new species, six are considered local endemics (except for Selaginella sematophylla) because of their restricted currently known distributions to one or two localities within a single state in Brazil. Additionally, we propose new synonymy for Selaginella palmiformis (syn. = Selaginella bahiensis subsp. manausensis, ≡ Selaginella manausensis) and Selaginella vestiens (syn. = Selaginella fragillima); the last species is endemic to Brazil, recorded in the states of Goiás and Minas Gerais. Finally, based on literature discussed and this study, we conclude that the number of well-documented Brazilian Selaginella species is 61, of which 58 are native and three introduced and naturalized. These statistics are likely to change with further work on Selaginella from Brazil

Morphological and phylogenetic evidence that the novel leaf structures of multivein Selaginella schaffneri are derived traits

Microphylls, simple leaves with a single vein and no leaf gap, are the typical lycophyte leaves. However, Selaginella schaffneri has complex veins. Structural features and phylogeny associated with this unusual venation have remained unknown. We studied the leaf, venation, spore structures, and phylogeny of S. schaffneri, with S. erythropus as a typical Selaginella for comparison. Leaf veins of both S. schaffneri and S. erythropus originate from a single vascular strand in the stem and have no leaf gaps. In S. schaffneri, this single vascular strand prominently enlarges as a hub-like vein node at the leaf base and then divides multiply in the leaf blade. Unusual structures, more commonly found in angiosperms, are revealed, including vessels, bundle sheath cells, three stomatal types, and differentiated mesophyll tissue. Other unusual structures include transparent zones on the leaf margin and a complex open hexagonal three-dimensional structure on the megaspore walls. Fifty one concatenated protein-coding genes from plastomes were used to construct the phylogeny of S. schaffneri within Selaginellaceae, which shows that S. schaffneri, together with the sanguinolenta group, is the earliest-diverging lineage of subgenus Stachygynandrum. The unusual structures of S. schaffneri are consistent with drought resistance. However, these structures are not known in more basal members of Selaginella and appear to be derived in S. schaffneri. The leaf veins of S. schaffneri, originating from the branching of a single vein, imply a variation on a microphyll. Despite the general simplicity of structure in Selaginella, S. schaffneri shows unusual structural homoplasy with angiosperms in these traits.Ministry of Science and Technology, Taiwan12 month embargo; available online: 25 November 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

A community-derived classification for extant lycophytes and ferns

Phylogeny has long informed pteridophyte classification. As our ability to infer evolutionary trees has improved, classifications aimed at recognizing natural groups have become increasingly predictive and stable. Here, we provide a modern, comprehensive classification for lycophytes and ferns, down to the genus level, utilizing a community-based approach. We use monophyly as the primary criterion for the recognition of taxa, but also aim to preserve existing taxa and circumscriptions that are both widely accepted and consistent with our understanding of pteridophyte phylogeny. In total, this classification treats an estimated 11 916 species in 337 genera, 51 families, 14 orders, and two classes. This classification is not intended as the final word on lycophyte and fern taxonomy, but rather a summary statement of current hypotheses, derived from the best available data and shaped by those most familiar with the plants in question. We hope that it will serve as a resource for those wanting references to the recent literature on pteridophyte phylogeny and classification, a framework for guiding future investigations, and a stimulus to further discourse