ABSTRACT Plagiochilaceae is a family of leafy liverworts that are distributed worldwide. It is of great importance due to its taxonomic and ecological implications among bryophytes. Most species of the family belong to the genus Plagiochila, but there is no consensus regarding its infrageneric circumscription. There have been few palynological studies involving Plagiochilaceae and Plagiochila. Here, we describe the spore morphology of seventeen species of Plagiochila and discuss the taxonomic value of palynological characters for these taxa. The spores were processed by standard palynological techniques and analyzed using light and electron microscopy. The spores were found to be apolar, spheroidal, released monads that vary in size from 13µm to 58µm (small to large size). The sporoderm comprises an intine (stratified), a nexine, and a sexine. The spore surface is ornamented with granules that vary in shape and morphology, thus allowing the studied species to be grouped into four spore types: regular and delicate granulate, irregular and coarse granulate, long granules with flattened apices, and long and straight granules. Hierarchical cluster analysis revealed five different groups of species, evidencing the importance of spore information for taxonomic and phylogenetic studies.

ABSTRACT Palynological studies of bryophytes are critical for evaluating the taxonomic relevance of their spores. They also provide important support to paleoecological investigations that, usually, treat bryophytes as a whole, which does not permit the evaluation of specific functional traits of a special taxonomic unit. The present study investigated the morphology and ultrastructure of spores of five species of Erpodiaceae (Bryophyta), and assessed the implications for taxonomy and the recognition of spores of past records. Erpodiaceae includes corticolous and saxicolous plants that are widely distributed throughout tropical and temperate regions. The spores were found to be isomorphic and apolar with a subcircular amb, granulate, inaperturate. The sporoderm possesses a perine, an exine and a stratified intine. The perine is largely responsible for spore surface ornamentation. The occurrence of exine projections, in isolation or sustaining the elements of the perine, characterizes sporoderm structure with features similar to that of a semitectum, a distinctive characteristic that has not been reported previously for bryophyte spores.

ABSTRACT Amphidium Schimp. is characterized by cushion-forming erect primary stems, linear-lanceolate leaves, and gymnostome capsules. The phylogenetic position of Amphidium is uncertain, with the genus having been variously included in Zygodontaceae Schimp., Rhabdoweisiaceae Limpr., Orthotrichaceae Arn. and Amphidiaceae M. Stech. A palynological investigation was performed of the three species of the genus that occur in the Americas: Amphidium lapponicum (Hedw.) Schimp., Amphidium mougeotii (Bruch & Schimp.) Schimp., and Amphidium tortuosum (Hornsch.) Cufod. Spores were observed and measured for greatest diameter under light microscopy both before and after acetolysis. Non-acetolyzed spores were observed under scanning electron microscopy to assess surface ornamentation of the sporoderm. All spores observed were smaller than 20 µm and heteropolar, with surface ornamentation reflecting a combination of different elements, such as gemmae, rugulae and perforations. The palynological characteristics observed here suggest that the genus Amphidium, and thus its contained species, be placed in their own family.

ABSTRACT In bryophytes, establishment can occur by a sexual or asexual process, but the production of spores enables colonization of a wider range of habitats and substrates than can asexual propagules. Successful germination is critical for establishment in a new environment. This paper addresses germination and sporeling development in Frullania ericoides, a leafy liverwort species. Fresh spores were inoculated in vitro in different culture strengths of Knop’s nutrient solution (one-fourth strength, half strength, full strength, one and a half strength and double strength), in order to evaluate the effects of this solution on spore germination and on the development of external protonema. On the first assessment, spore germination was observed at all the concentrations. Germination was endosporic, with cell division and proliferation, resulting in a globular protonema, within the spore wall. Beginning at the fourth week, the development of tightly concave primordial leaves was observed in all but the double-strength medium. Throughout the period of study, the treatments with lower concentrations exhibited external protonema with greater lengths. The double-strength treatment was statistically different from other treatments in at least two parameters. The results of this study demonstrate the potential of in vitro culture techniques for bryophyte spore studies and germplasm preservation.

No presente trabalho foram analisados os esporos de sete espécies da família Sematophyllaceae Broth. (Bryophyta) ocorrentes em três áreas de Mata Atlântica. Para análise da morfologia externa dos esporos, utilizou-se o método direto em gelatina glicerinada e para as medidas foi utilizado o método de acetólise. Foram medidos os diâmetros maior e menor (em vista polar) e a espessura da parede. As análises foram realizadas sob microscópio de luz e microscópio eletrônico de varredura. Após a realização das medidas, realizou-se a análise estatística e estas foram apresentadas em tabelas. Os esporos são isomórficos, de tamanho pequeno a médio, heteropolares, de amb subcircular, com região apertural proximal e superfície granulada. A região apertural é irregular. As variações encontradas entre os esporos das diferentes espécies estão relacionadas ao tamanho dos esporos e à distribuição dos elementos de ornamentação.

In the present work the spores of seven species of the family Sematophyllaceae Broth. (Bryophyta) from three areas of Mata Atlântica were analyzed. For the spores' external morphology analysis, the direct method in glycerined gelatin was used and for the measurements the method of acetolysis was used. The largest and smaller diameters (in polar view) and the thickness of the wall were measured. The analysis was carried under optical microscope and scanning electronic microscope. The spores are isomorphic, from small to medium size, heteropolars, of subcircular amb, with proximalapertural region and granulated surface. The apertural region is irregular. The variations found between the spores of the different species are related to the size of the spores and the distribution of the trimming elements.

A morfologia dos esporos é descrita para todos os seis gêneros de Polytrichaceae ocorrentes no Brasil baseando-se no estudo, em microscopia de luz e eletrônica de varredura, de 13 das aproximadamente 30 espécies da família nativas para o país. Também é apresentada a discussão sobre sua importância taxonômica. Os esporos foram estudados antes e após o método da acetólise. Os resultados indicam Polytrichaceae como euripalinológica. A superfície dos esporos de Atrichum androgynum (Müll. Hal.) A. Jaeger é formada por grânulos regulares, com gemas isoladas. Os esporos de Itatiella ulei P. Beauv. e das espécies de Oligotrichum Lam. & DC. são de tamanho pequeno a médio, com báculos, processos alongados, clavas e pilos na superfície. Espécies de Pogonatum P. Beauv. possuem esporos de tamanho muito pequeno a pequeno, com superfície granulada. Os esporos de Polytrichadelphus pseudopolytrichum (Raddi) G. L. Sm. são de tamanho muito pequeno a pequeno, com ornamentação formada por diminutos espinhos lisos. Nas espécies de Polytrichum Hedw., os esporos são de tamanho pequeno e a ornamentação é formada por processos espinhosos ornamentados a grânulos.

Spore morphology is described for all six genera of Brazilian Polytrichaceae based on light and scanning electron microscopy study of 13 species of the approximately 30 species of the family native to the country. Discussion on its taxonomic importance is also provided. Spores were analyzed before and after the acetolysis method. Polytrichaceae is eurypalynous. The spore surface of Atrichum androgynum (Müll. Hal.) A. Jaeger has regular granules and isolated gemmae. The spores of Itatiella P. Beauv. and Oligotrichum Lam. & DC. species are small to medium size, with bacula, elongated processes, clavae and pila on the surface. Species of Pogonatum P. Beauv. gathers spores of very small to small size, granulate surface. Polytrichadelphus pseudopolytrichum (Raddi) G. L. Sm. spores are very small to small size, and ornamentation formed by reduced smooth spines. In Polytrichum Hedw. species the spores are small and ornamentation is formed by ornamented spine-like processes to granules.

Chonecolea doellingeri (Nees) Grolle é uma espécie urbanizada que cresce, preferencialmente, sobre estipe de palmeira ou outras árvores. Sua distribuição geográfica foi ampliada para o estado do Mato Grosso do Sul e, também, para municípios de outros estados já referidos. Algumas associações da espécie com outras briófitas são apresentadas. Dados palinológicos, baseados em observações sob microscopia de luz (ML) e microscopia eletrônica de varredura (MEV), também estão incluídos no trabalho.

Chonecolea doellingeri (Nees) Grolle is an urbanized species that grows preferentially on palm-tree trunks and other trees. Its geographical distribution was extended to the state of Mato Grosso do Sul and, also, to cities of other aforementioned states. Some associations of these species with other bryophytes are presented. Palynological data, based on observations under light microscopy (LM) and scanning electron microscopy (SEM), are also included.