Abstract The morphometric knowledge about the spores of the Ctenitis has not yet been deepened. Considering the folded spores of this genus which inhabit the Southern Cone of America the aims were to increase infrageneric knowledge, to evaluate the relationship among the morphometric characters of the folded spores in these Ctenitis species and to verify the spore’s morphometry as a taxonomic tool. This study was performed with herbarium material. The spores were analyzed with light microscopy (LM) and scanning electron microscopy (SEM). The variables analyzed were: major and minor equatorial diameter, polar diameter, length of the laesura and length, width and height of the folds. The test chosen to analyze the study variables was ANOVA. Four spore sets are proposed. The “elongate-type” is made up of C. aspidioides and C. nervata. The “medium-type” is made up of C. anniesii, C. distans, C. falciculata and C. paranaensis. The “handle shape-type” is represented by C. bigarellae, C. eriocaulis and C. submarginalis. Finally, the “short-type”, consists only of C. deflexa. The morphometric data of spores together with the statistical analysis provided useful information for the distinction of some Ctenitis species studied in the Southern Cone of America. These results contribute to the studies aeropalynologycal and palaeopalynological.

Resumen El conocimiento morfométrico sobre las esporas de la Ctenitis aún no se ha profundizado. Considerando las esporas plegadas de este género que habitan el Cono Sur de América, los objetivos de este estudio fueron aumentar el conocimiento infragenérico, evaluar la relación entre los caracteres morfométricos de las esporas plegadas en estas especies de Ctenitis y verificar la morfometría de las esporas como herramienta taxonómica. Este estudio se realizó con material de herbario. Las esporas se analizaron con microscopia óptica (MO) y microscopía electrónica de barrido (MEB). Las variables analizadas fueron: diámetro ecuatorial mayor y menor, diámetro polar, largo de lesura y largo, ancho y alto de los pliegues. La prueba elegida para analizar las variables de estudio fue ANOVA. Se proponen cuatro conjuntos de esporas. El “tipo-alargado” está formado por C. aspidioides y C. nervata. El “tipo-medio” está compuesto por C. anniesii, C. distans, C. falciculata y C. paranaensis. El “tipo-forma de mango” está representado por C. bigarellae, C. eriocaulis y C. submarginalis. Finalmente, el “tipo-corto”, consiste solo en C. deflexa. Los datos morfométricos junto con el análisis estadístico brindaron información útil para la distinción de algunas especies de Ctenitis estudiadas en el Cono Sur de América. Estos resultados contribuyen a estudios aeropalinológicos y paleopalinológicos.

Abstract Calilegua National Park is located in the Southeast of the province of Jujuy, Argentina. It is comprised of different districts within the Yungas Biogeographic Province, where conditions are optimal for fern development. The palynological studies with light microscopy in this area are very limited. The aim of this work is to present the morphology of spores from 42 taxa belonging to 9 families of isosporate ferns that grow in this protected area. The study was carried out with herbarium material. The families studied are Anemiaceae, Aspleniaceae, Athyriaceae, Blechnaceae, Cyatheaceae, Cystopteridaceae, Dennstaedtiaceae, Dryopteridaceae, and Equisetaceae. According to the spore aperture type, 35 taxa are monolete, five trilete, and two alete. The spores are yellowish, light to dark brown or brown greenish. The largest spores belong to Anemia australis and the smallest to Asplenium argentinum. Equinate, folded, cristate, alate, reticulate, ridged, psilate, verrucate, and baculate spores were observed. For the first time, the spores of 27 species are illustrated under a light microscope. An identification key of the spores is also provided. The morphological characteristics of the spores allowed for the identification of 23 species, contributing to spore bank analysis, aeropalynological and paleopalynological studies, and taxonomic identifications.

Resumen Pleopeltis macrocarpa y Microgramma mortoniana son dos helechos epífitos de la familia Polypodiaceae hallados con baja frecuencia en la Reserva Natural Punta Lara (Buenos Aires, Argentina). El objetivo de este trabajo fue estudiar la morfogénesis de gametófitos epífitos para fortalecer poblaciones vulnerables y contribuir a su conservación. Se recolectaron hojas fértiles. Las esporas se sembraron en placas de Petri con medio de cultivo Dyer. Las esporas se caracterizaron por ser monoletes, elipsoidales, amarillentas y con ornamentación verrucosa. La germinación fue del tipo Vittaria y el desarrollo del gametofito es del tipo Drynaria. El esporofito de P. macrocarpa surgió a los 500 días y el de M. mortoniana a los 120. El patrón de germinación, el desarrollo del gametofito, el glóbulo lipídico en la célula protálica y los pelos unicelulares capitados en el margen podrían considerarse en la sistemática del grupo. La demora en la formación de esporofitos a través de la reproducción sexual, permite inferir que el éxito de su propagación estaría sujeto a la reproducción vegetativa.

Abstract The Punta Lara Natural Reserve is located on the riverside of the La Plata River in the province of Buenos Aires, Argentina. It is the Southernmost relict in the world of subtropical riparian forest. The epiphytic ferns studied in this work belong to the Polypodiaceae family: Microgramma mortoniana and Pleopeltis macrocarpa. Plant communities are subject to high levels of anthropization and introduction of exotic species. The goals of this work are to provide information on the morphogenesis of epiphytic gametophytes and to extend knowledge of their life cycles, contributing to their conservation. Sowing was carried out in Dyer medium. In both species the spores are monolete, ellipsoidal, yellowish and with verrucate sculpture. The equatorial diameter is 60-61 μm, the polar diameter is 39-42 μm. The germination is the Vittaria type; in M. mortoniana occurs at 20 days, while in P. macrocarpa occurs at six days. The filaments are uniseriate of 3-6 cells in length. The gametophyte development is Drynaria type. The cordated form is given after 40 days. In M. mortoniana, buds originated after 40 days. In P. macrocarpa, after 120 days, clathrate trichomes scale-like appear mainly on the margins of the gametophyte. The gametangia are typical of leptosporangiate ferns. The sporophyte of M. mortoniana emerged after 120 days and that of P. macrocarpa arose after 500 days, its blades are simple, spatulate and unicellular and multicellular branching hairs were observed. The germination pattern, gametophyte development, the presence of a lipid globule in the prothalic cell and the formation of unicellular capitated hairs are relevant characters that could be considered for systematic group. The delay in the formation of sporophytes through sexual reproduction, allows us to infer that the success of their establishment in situ would be given by the vegetative reproduction through creeping rhizomes and buds of gametophytes. Rev. Biol. Trop. 66(3): 1078-1089. Epub 2018 September 01.