Paulo H. Labiak

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).

Phylogeny and Character Evolution of the Bolbitidoid Ferns (Dryopteridaceae)

We performed a phylogenetic analysis of the traditionally recognized genera of bolbitidoid ferns (i.e., Arthrobotrya, Bolbitis, Elaphoglossum, Lomagramma, and Teratophyllum) using two noncoding chloroplast spacers: trnL‐trnF and rps4‐trnS. The sampling included 57 species, of which 55 had not been sequenced previously. The results supported the monophyly of bolbitidoid ferns and of Arthrobotrya, Elaphoglossum, Lomagramma, and Teratophyllum; however, Bolbitis was resolved as polyphyletic. A clade of eight Neotropical species currently placed in Bolbitis is sister to Elaphoglossum, not the other species of Bolbitis. We refer to this group of species as the Bolbitis nicotianifolia clade. Lomagramma (or Bolbitis) guianensis, whose generic placement has been uncertain, was found to belong to the B. nicotianifolia clade. Bolbitis s.s. was resolved sister to the rest of the bolbitidoid ferns, which are in turn divided into two clades, one consisting of Elaphoglossum and the B. nicotianifolia clade and the other of Lomagramma, Teratophyllum, and Arthrobotrya. We optimized 34 morphological characters on the resulting phylogenetic tree. The characters found to be synapomorphic for bolbitidoid ferns were ventral root insertion, elongated ventral meristeles, sterile‐fertile leaf dimorphism, acrostichoid sori, and the absence of hairs on the leaves. Other characters, such as articulate pinnae, venation patterns, laminar buds, paraphyses, and growth habit, are discussed in relation to the clades they support at different nodes on the tree. The bolbitidoid ferns show a transition series from terrestrial (Bolbitis) to hemiepiphytic (the B. nicotianifolia clade, Arthrobotrya, Lomagramma, and Teratophyllum) to epiphytic (Elaphoglossum). A sister‐species relationship between the Neotropical Bolbitis serratifolia and the African Bolbitis acrostichoides was recovered, supporting their relationship as previously postulated on the basis of morphology.

Synopsis of Mickelia, a newly recognized genus of bolbitidoid ferns (Dryopteridaceae)

Our recent molecular phylogenetic study revealed a previously unrecognized clade of six species that is sister to Elaphoglossum. Within this clade, four species are currently classified in Bolbitis, one in Lomagramma, and one in Acrostichum. For this clade, we propose the name Mickelia, with M. nicotianifolia as the type species. We also make new combinations for the species in our phylogenetic study shown to belong to Mickelia (M. bernoullii, M. guianensis, M. hemiotis, M. nicotianifolia, M. oligarchica, and M. scandens) and two other species believed to belong to the clade based on morphology (M. lindigii, M. pergamentacea). A new hybrid and two new species are also described (M. ×atrans, M. furcata, and M. pradoi). In total, Mickelia consists of ten species and one hybrid. It is entirely neotropical. We provide a key to the genera of bolbitidoid ferns and a synopsis of Mickelia that gives for each species a complete synonymy, geographical distribution, comparative discussion, and illustration.ResumoAnálises filogenéticas recentes revelaram a existência de uma clado composto por seis espécies, irmão de Elaphoglossum. Das espécies incluídas nestas análises, quatro são atualmente tratadas em Bolbitis, uma em Lomagramma, e uma em Acrostichum. A este clado propomos o nome Mickelia, com M. nicotianifolia sendo sua espécie-tipo. Neste trabalho são apresentadas as novas combinações para as espécies de Mickelia, tanto as que foram tratadas nas análises filogenéticas (M. bernoullii, M. guianensis, M. hemiotis, M. nicotianifolia, M. oligarchica e M. scandens), quanto para duas outras que são aqui incluídas com base em evidências morfológicas (M. lindigii e M. pergamentacea). Um híbrido novo e duas espécies novas são também descritos (M. ×atrans, M. furcata e M. pradoi). No total, Mickelia compreende dez espécies e um híbrido. O gênero é inteiramente neotropical, e é caracterizado pelo hábito hemiepifítico, nervuras anastomosadas, e pela ausência de gemas (essas, se presentes, surgindo próximas à junção da pina com a raque). São apresentadas uma chave para os gêneros das samambaias bolbitidoides, e uma sinopse para Mickelia contendo uma lista completa de sinônimos, dados sobre distribuição geográfica, discussões comparativas e ilustrações.

Molecular phylogeny, character evolution, and biogeography of the grammitid fern genus Lellingeria (Polypodiaceae)

UNLABELLED PREMISE OF THE STUDY The recognition of monophyletic genera for groups that have high levels of homoplastic morphological characters and/or conflicting results obtained by different studies can be difficult. Such is the case in the grammitid ferns, a clade within the Polypodiaceae. In this study, we aim to resolve relationships among four clades of grammitid ferns, which have been previously recovered either as a polytomy or with conflicting topologies, with the goal of circumscribing monophyletic genera. • METHODS The sampling included 89 specimens representing 61 species, and sequences were obtained for two genes (atpB and rbcL) and four intergenic spacers (atpB-rbcL, rps4-trnS, trnG-trnR, and trnL-trnF), resulting in a matrix of 5091 characters. The combined data set was analyzed using parsimony, likelihood, and Bayesian methods. Ninety-six morphological characters were optimized onto the generated trees, using the parsimony method. • KEY RESULTS Lellingeria is composed of two main clades, the L. myosuroides and the Lellingeria s.s. clades, which together are sister to Melpomene. Sister to all three of these is a clade with two species of the polyphyletic genus Terpsichore. In the L. myosuroides clade, several dispersal events occurred between the neotropics, Africa, and the Pacific Islands, whereas Lellingeria s.s. is restricted to the neotropics, with about 60% of its diversity in the Andes. • CONCLUSIONS Overall, our results suggest that Lellingeria is monophyletic, with two clades that are easily characterized morphologically and biogeographically. Morphological characters describing the indument are the most important to define the clades within the ingroup. A small clade, previously considered in Terpsichore, should be recognized as a new genus.

Not so Neotropical After All: The Grammitid Fern Genus Leucotrichum (Polypodiaceae) is Also Paleotropical, as Revealed by a New Species from Madagascar

Abstract Based on morphological and molecular evidence (DNA sequences from six plastid regions: atp&bgr;, rbcL, trnG-trnR, trnL-trnF, atp&bgr;-rbcL, and rps4-trnS), the new fern species Leucotrichum madagascariense is described from Madagascar, where it is found in the North (Marojejy), Centre (Andringitra), and South (Andohahela) regions. Leucotrichum madagascariense has long, whitish laminar hairs, among the other distinguishing characters of the genus: arching fronds, laminar apices subconform to the lateral pinnae, dark sclerenchyma covered by the green laminar tissue, and laterally marginate petioles. Its most remarkable feature is the lack of rhizome scales, a character that is shared with the Neotropical L. pseudomitchelliae. However, our phylogenetic results suggest that this character has evolved twice independently within the genus. In contrast, the sister relationship between the new Madagascan species and the group composed of L. schenckii and L. mortonii is morphologically supported by linear and deeply pinnatifid laminae, incised 2/3–3/4 of the way to the rachis along its length. Leucotrichum madagascariense is the only representative of the genus known from the Old World. Because it is nested within a clade of five Neotropical species, we hypothesize that its occurrence outside the Neotropics results from one long-distance dispersal event from America, likely southeastern Brazil, to Madagascar.

Alansmia, a new genus of grammitid ferns (Polypodiaceae) segregated from Terpsichore

Alansmia, a new genus of grammitid ferns is described and combinations are made for the 26 species known to belong to it. Alansmia is supported by five morphological synapomorphies: setae present on the rhizomes, cells of the rhizome scales turgid, both surfaces of the rhizome scales ciliate, laminae membranaceous, and sporangial capsules setose. Other diagnostic characters include pendent fronds with indeterminate growth, concolorous, orange to castaneous rhizome scales with ciliate or sometimes glandular margins, hydathodes often cretaceous, and setae simple, paired or stellate. The group also exhibits the uncommon characteristic of producing both trilete and apparently monolete spores, sometimes on the same plant. New combinations are made for Alansmia alfaroi, A. bradeana, A. canescens, A. concinna, A. contacta, A. cultrata, A. dependens, A. diaphana, A. elastica, A. glandulifera, A. heteromorpha, A. immixta, A. kirkii, A. lanigera, A. laxa, A. longa, A. monosora, A. reclinata, A. semilunaris, A. senilis, A. smithii, A. spathulata, A. stella var. stella, A. stella var. flava, A. turrialbae, A. variabilis, A. xanthotrichia. Lectotypifications are made for Alansmia concina, A. variabilis, Polypodium ciliare, P. flexile, and P. ovalescens. The genus is named in honor of pteridologist Alan R. Smith.

PERISPORE MORPHOLOGY OF BOLBITIDOID FERNS (DRYOPTERIDACEAE) IN RELATION TO PHYLOGENY

The perispores of 48 species of bolbitidoid ferns (Mickelia, Arthrobotrya, Bolbitis, Elaphoglossum, Lomagramma, and Teratophyllum) were studied with an SEM. The species studied were those used in a published phylogenetic analysis. For each species, five perispore characters were scored and optimized onto a published molecular tree. A loose, nonappressed perispore with broad folds optimizes as ancestral for the bolbitidoids. The only exception is Lomagramma, for which the perispore adheres tightly to the exospore—a character state that optimizes as a synapomorphy for that genus. In the bolbitidoids, thin crests evolved from broad folds seven times. The presence of thin crests in Mickelia optimizes as a synapomorphy for that genus. The presence of fine surface detail, here termed “microstructure,” was present in nearly all bolbitidoids and optimized as ancestral. Microstructure consisted of spicules, minute crests, and verrucae. The presence of verrucae optimizes as a synapomorphy for Lomagramma. The perispore of Bolbitis appendiculata is visually striking because it is highly reticulate throughout, a character that is autapomorphic in this analysis. No correspondence was observed between perispore characters and the transition series going from terrestrial (Bolbitis) to hemiepiphytic (Mickelia, Arthrobotrya, Lomagramma, and Teratophyllum) to epiphytic (Elaphoglossum) genera. The spore images of all species studied are publicly available at http://www.plantsystematics.org.

The Phylogenetic Relationship of Tectaria brauniana and Tectaria nicotianifolia, and the Recognition of Hypoderris (Tectariaceae)

Abstract Tectaria brauniana and T. nicotianifolia are unusual in their genus by having creeping rhizomes and two-ranked leaves. Tectaria brauniana is further unusual by having free veins. These rhizome characters of both species, and the free veins of T. brauniana, are typical of Triplophyllum and suggest a relationship to that genus instead of Tectaria. To determine the phylogenetic relationships of T. brauniana and T. nicotianifolia, we used molecular evidence from four plastid DNA markers (rbcL, rps4-trnS, trnG-trnR, and trnL-trnF) to generate a phylogenetic hypothesis for the Tectariaceae. The analysis included the tectarioid genera Arthropteris, Hypoderris, Psammiosorus, Pteridrys, Tectaria, and Triplophyllum. Tectaria brauniana and T. nicotianifolia were recovered as sister to Hypoderris brownii, and these three species were sister to Triplophyllum. These two clades were sister to the rest of Tectaria. Thus, to preserve the monophyly of Tectaria, T. brauniana and T. nicotianifolia are here classified in Hypoderris, a genus previously considered monotypic. We make the following new combination: H. nicotianifolia. In this expanded sense, Hypoderris is characterized by creeping rhizomes, two-ranked leaves, and spiny perispores. The genus occurs in the Caribbean region, Central America, and the Andes from northern Venezuela to Bolivia. A key and illustrations are given for the three species now recognized in Hypoderris.

Megalastrum (Dryopteridaceae) in Brazil, Paraguay, and Uruguay

Abstract We provide keys, descriptions, illustrations, full synonymies, maps, and a list of specimens examined for species of Megalastrum found in Brazil, Paraguay, and Uruguay. Eighteen species are recognized, including seven new ones: M. albidum, M. brevipubens, M. indusiatum, M. littorale, M. organense, M. retrorsum, and M. substrigosum. The species occur primarily in the coastal mountains; none occur in Amazonia. The mountains of coastal Brazil are a center of endemism and diversity for the genus.