Pedro B. Schwartsburd

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.

Diversity of ferns and lycophytes in Brazil

This compilation of ferns and lycophytes in Brazil is an update of the one published in 2010 in Catalogo de Plantas e Fungos do Brasil. The methodology consisted in collecting data from regional checklists, taxonomic revisions, and selected databases. Invited specialists improved the list accessing a website housed at the Jardim Botânico do Rio de Janeiro. The results show 1,253 species: 1,111 of ferns and 142 of lycophytes. This number is 6.5% higher than the previous one (1,176 spp.). The percentage of endemic species decreased from 38.2% to 36.7%. We recognized 36 families and 133 genera (vs. 33 families, 121 genera in 2010). The 10 most diverse families are Pteridaceae (196 spp.), Dryopteridaceae (179), Polypodiaceae (164), Hymenophyllaceae (90), Thelypteridaceae (86), Aspleniaceae (78), Lycopodiaceae (64), Selaginellaceae (55), Anemiaceae (51), and Cyatheaceae (45). The three most diverse genera are still Elaphoglossum (87 spp.), Thelypteris (85), and Asplenium (74). The richest phytogeographic domain continues to be in the Atlantic Rainforest with 883 species which also has the largest number of endemic and threatened species, followed by the Amazon Rainforest (503), Cerrado (269), Pantanal (30), Caatinga (26), and Pampa (eight). Minas Gerais remains as the richest state (657 spp. vs. 580 in 2010).

Subspecies of Hypolepis rugosula (Dennstaedtiaceae; Pteridophyta) around the world: morphological and biogeographic perspectives

The “Hypolepis rugosula complex” has been the subject of great debate among pteridologists: some have considered H. rugosula a single subcosmopolitan (or circum-Antarctic) species, whereas others have considered it a species-complex, encompassing several species. In the 1920s and 1930s, four geographically distinct varieties of H. rugosula were recognized. In this work, we present a new taxonomy (with new combinations and statuses, as well as typification and full synonymy), together with complete distribution data for the species, with an infraspecific classification based on morphological and biogeographic perspectives. Hypolepis rugosula occurs in southern temperate regions and high-elevation tropical regions of the Americas, Africa (including Madagascar), Oceania and the Philippines, as well as in some isolated oceanic volcanic islands (e.g., Saint Helena and Tristan da Cunha). Here, 15 geographically distinct subspecies are recognized. All subspecies are geographically segregated from each other, except in New Zealand, where two occur sympatrically—possibly due to two different arrival and colonization times. Four patterns of “indument” (referring to catenate and glandular hairs collectively) are distinguished. Different lineages are successful in their respective habitats; we observed two lineages with different ploidy levels (tetraploid and octoploid). Although long-distance dispersal is the best explanation for the extant distribution of H. rugosula; we do not exclude vicariance as a possible explanation for their occurrence on the land masses that were once united as Gondwana. Therefore, we are assuming that a fern species could remain unchanged for more than 70 Myr, and we are adopting the refugia theory, albeit with a different focus.

A Taxonomic Revision of the South American Species of Hypolepis (Dennstaedtiaceae), Part I

Abstract Hypolepis is a subcosmopolitan genus with ca. 80–90 taxa worldwide, and with few taxonomic studies. The present work is a taxonomic revision of the South American species, including Cocos Island (Costa Rica). It has been based, mainly, on the morphological study of nomenclatural types and exsiccates from European and South American herbaria, plus one herbarium from New Zealand and another from the United States of America. Some species were also studied in nature. For South America (incl. Cocos Island), 26 species are here recognized, and a total of 31 taxa (species, subspecies, varieties, and hybrids). Among these are four new taxa: H. galapagensis, H. ×glabra, H. ×paulistana, and H. pedropaloensis. The geographical distribution patterns were classified into nine categories. Minimum and maximum elevations are strong limiting factors of distribution. The taxonomic treatment includes keys to taxa, new and complete synonymies, typifications, taxa description, distribution maps, illustrations, studi...

The Identity of Polypodium gyroflexum ( = Pleopeltis gyroflexa, Comb. Nov. – Polypodiaceae)

Abstract Polypodium gyroflexum has been a forgotten name since 1940. It is, in fact, an earlier name to a fern recently known as Pleopeltis repanda. Here, I provide the new combination, lectotypification, a detailed characterization, and illustrations for Pleopeltis gyroflexa, comb. nov., plus the synonymization of Pleopeltis repanda. Pleopeltis gyroflexa is known from two populations located ca. 2500–3000 km from each other, and they show some slight morphological differences. The gap between them comprises Amazon forest, the Amazon River, croplands, disturbed areas, and semi-desert vegetation (Caatinga). A vegetation map with their distribution data is also provided.

Eriosorus areniticola (Pteridaceae), a New Species from Brazil

ABSTRACT We describe and illustrate a new species, Eriosorus areniticola, and compare it with E. myriophyllus, the species to which it is most similar. This new species is endemic to southeastern and southern Brazil. It resembles a small form of E. myriophyllus, but differs by the absence of glandular hairs on rachises and laminar tissue, smaller leaf size, and distinct habitat.

Schizaeales (Filicopsida, Tracheophyta) of Viçosa, Minas Gerais, Brazil, with special reference to hybrids

As part of a floristic project dealing with the ferns and lycophytes from the region of Viçosa in Minas Gerais, Brazil, we present a taxonomic treatment of the Schizaeales. Seven species of Anemia occur in the region: A. hirsuta, A. hispida, A. mandioccana,A. mickelii, sp. nov., A. phyllitidis, A. raddiana, and A. tomentosa var. tomentosa. Based on morphology and field studies, we found four hybrids: A. hirsuta × A. mickelii (= A.×mexiae, hybrid nov.), A. hispida × A. mickelii (= A.×semihispida, hybrid nov.), A. hirsuta × A. phyllitidis (= A. ×semihirsuta), and A. mickelii × A. ×semihirsuta (= A. ×promiscua, hybrid nov.). Two species of Lygodium occur in the region (L. venustum and L. volubile) and their hybrid, L. ×fayae. Among the five hybrids documented here, three are reported for the first time in the literature, and two are reported for the first time in Brazil. We also present keys to species and hybrids, descriptions, illustrations, lists of examined material, and updated geographical distributions of all taxa.ResumoComo parte de um projeto floristico que trata de samambaias e licófitas da região de Viçosa en Minas Gerais, Brasil, é apresentado o tratamento taxonômico de Schizaeales. Na região, sete espécies de Anemia ocorrem: A. hirsuta, A. hispida, A. mandioccana,A. mickelii, sp. nov., A. phyllitidis, A. raddiana e A. tomentosa var. tomentosa. Baseado na morfologia e estudos em campo, foi possível observar quatro eventos de hibridização entre elas: A. hirsuta × A. mickelii (= A.×mexiae, hybrid nov.), A. hispida × A. mickelii (= A.×semihispida, hybrid nov.), A. hirsuta × A. phyllitidis (= A. ×semihirsuta), and A. mickelii × A. ×semihirsuta (= A. ×promiscua, hybrid nov.). Também, duas espécies de Lygodium ocorrem (L. venustum e L. volubile) e seu híbrido, L. ×fayae. Dentre os cinco híbridos encontrados, três são documentados pela primeira vez na literatura, e dois pela primeira vez no Brasil. Em adição, são apresentados chaves de identificação, descrições, ilustrações, lista de material examinado e distribuição geográfica atualizada de todos os táxons.

Oleandra (Oleandraceae) in the Brazilian Atlantic Forest

Abstract We present a taxonomic treatment of the genus Oleandra in the Brazilian Atlantic Forest. Five endemic species and one putative hybrid are recognized: O. australis, sp. nov. (endemic to the state of Paraná), O. baetae (endemic to state of Minas Gerais), O. brasiliana, sp. nov. (widespread along the Brazilian Atlantic Forest), O. hirta (endemic to the state of Rio de Janeiro), O. quartziticola, sp. nov. (endemic to the state of Espírito Santo), and O. baetae × O. brasiliana (from places of sympatry). The widely used name “Oleandra articulata” does not apply to the Brazilian Atlantic Forest species. All species are described, illustrated, and mapped.

Morpho-anatomical Studies and Evolutionary Interpretations of the Rhizomes of Extant Dennstaedtiaceae

Abstract Dennstaedtiaceae is a monophyletic, extant family of ferns with sub-cosmopolitan distribution and ca. 265 species. Rhizome morphology in the Dennstaedtiaceae is relatively well known, yet its anatomy has been poorly explored. We performed morpho-anatomical studies on 26 taxa from eight genera, mostly from Brazil, Japan, and New Zealand. Among the studied species, the main rhizome type is long-creeping with alternate phyllotaxy and a solenostele s. str. The exception is Blotiella lindeniana, which has ascending rhizomes with radial phyllotaxy and a dictyostele. A polycyclic solenostele was found in Dennstaedtia (“Patania”) cornuta, D. (“Patania”) dissecta, and two subspecies of Pteridium arachnoideum. Lateral-line aerenchyma characterized Blotiella lindeniana, Histiopteris incisa, Hypolepis spp., Paesia spp., and Pteridium arachnoideum subspp. The position of sclerified parenchyma in the cortex and pith varied among species. Our data enabled us to hypothesize evolutionary patterns of rhizome evolution in extant lineages of the Dennstaedtiaceae. The “Monachosorideae” has retained ancestral conditions: short-creeping to ascending rhizomes with dictyostele s. str. In the “Hypolepidoideae”, two notable changes occurred in Blotiella and Pteridium (in which the solenostele evolved into a polycyclic solenostele). In the “Dennstaedtioideae”, one notable change occurred in Dennstaedtia (“Patania”), namely parallel evolution with Pteridium (in which the polycyclic solenostele has also evolved). We present illustrations, morpho-anatomical descriptions, evolutionary inferences based on the available phylogeny, and supporting tools for studying the taxonomy, systematics, phylogeny, and paleontology of the group.

Aquatic ferns from Viçosa (MG, Brazil): Salviniales (Filicopsida; Tracheophyta)

This work presents the species of Salviniales occurring in the region of Viçosa, MG, Brazil. There, two species occur naturally (Azolla microphylla Kaulf. and Salvinia auriculata Aubl.), three spontaneously (Marsilea ancylopoda A. Braun, S. minima Baker, and S. molesta D.S. Mitch.), and one in cultivation (S. biloba Raddi). Both S. auriculata and S. molesta form dense mats, covering the whole lake areas; S. biloba also forms mats throughout its native distribution. We confirmed the alloploidy (pentaploidy) of S. molesta, due to the production of only hollow sporangia; we speculate aneuploidy for other taxa from Viçosa. We also confirmed the presence of nitrogen-fixing cyanobacterium, Anabaena azollae Strasburger (Nostocaceae), within the fronds of A. microphylla. We provide keys, descriptions, illustrations, taxonomic comments, and updated distribution data for all six taxa. We also propose new characteristics with taxonomic value and new morphological terminology for Salvinia.