Abstract The spore morphology and wall ultrastructure of 12 species of Ctenitis from Southern Cone of America were studied using light microscope, scanning and transmission electron microscope. The study was carried out with herbarium material from Argentine and Brazilian institutions. Equatorial diameters, polar diameters and laesura length were measured. The spores are monolete with echinate or folded ornamentation. In the echinate type, the spines are conical, with broad base and attenuate apex. In the rugate type, the folds are inflated, linear, sinuous, subglobose or handle-shape. The perispore surface is scabrate, rugulate, microverrucose or psilate. Stratification and ultrastructure in the species analyzed are very similar. The exospore is smooth and two-layered in section. Simple and branched channels are observed mainly in the outer exospore. The perispore is composed of two layers, the inner one forms the ornamentation and the outer covers all the outer and inner surfaces. Immature spores were found in all samples of C. fenestralis. The characteristics of the studied spores like macro-ornamentation, color and fold length provide relevant information to differentiate some species or groups of species within the genus.

Summary Background and aims : The morphological characteristics of the spores provide information for the identification of fern taxa. To deepen the analyses of the morphological characteristics of the spores of the isosporated ferns inhabiting the Punta Lara Nature Reserve using light microscopy. M&M : The spores of the isosporate ferns that grow in the Punta Lara Nature Reserve (Buenos Aires Province, Argentina) were studied under a light microscope. The study was carried out with fresh materials collected during three years (2016-2018) at different sites of the Reserve. Twenty fern taxa, 16 native and 4 exotic, were analysed. The registered characteristics were: colour, shape, major and minor equatorial diameters, polar diameter, length and characteristics of the laesura and wall ornamentation. Results : The colour of the spores may be yellow, light brown, dark brown and only in Equisetum they are green (chlorophyllous). Most spores are monolete (13 species), other trilete (6 species) and only one species has alete spores. The spore walls may be smooth, wrinkled, folded, verrucated, tuberculated, reticulated and winged. Conclusions : The morphology of the spores allows the identification of the ferns of the Reserve at a generic and specific level and provides information for palaeopalynological and aeropalynological studies and of soil spore banks.

Resumen Introducción y objetivo : Las características morfológicas de las esporas brindan información para la identificación de taxa de helechos. Profundizar los análisis de las características morfológicas de las esporas de los helechos isosporados que habitan en la Reserva Natural de Punta Lara utilizando microscopía óptica. M&M : Se estudiaron con microscopio óptico las esporas de helechos isosporados que crecen en la Reserva Natural Punta Lara (provincia de Buenos Aires, Argentina). El estudio fue llevado a cabo con material fresco colectado durante 3 años (20162018) en diferentes sitios de la Reserva. Se analizaron 20 taxa de helechos, 16 nativos y 4 exóticos. Las características registradas fueron: color, forma, diámetros ecuatoriales mayor y menor, diámetro polar, longitud y características de la lesura y ornamentación de la pared. Resultados : El color de las esporas puede ser amarillo, castaño claro, castaño oscuro y solo en el caso de Equisetum son verdes (clorofílicas). La mayoría de esporas son monoletes (13 especies), otras triletes (6 especies) y una sola especie posee esporas aletes. Las paredes de las esporas pueden ser lisas, plegadas, verrucosas, tuberculadas, reticuladas y ruguladas-crestadas. Conclusiones : La morfología de las esporas permite la identificación de los helechos de la Reserva a nivel de género y especie y aporta información para estudios paleopalinológicos, aeropalinológicos y de bancos de esporas del suelo.

Abstract Farrell, E. E.; L. R. Mautino & S. S. Garralla. 2020. Pollen Morphology of natives Nyctaginaceae of Argentina. Darwiniana, nueva serie 8(1): 292-308. The pollen morphology of Argentinian genera and species of Nyctaginaceae was analized in order to provide detailed information and contribute for their identification in actual and fossil pollen dispersed. The Nyctaginaceae family in Argentina, is composed of 8 genera with 19 species included in the following tribes: Boungainvilleeae: Bougainvillea (B. campanulata, B. infesta, B. praecox, B. spinosa, B. stipitata). Colignonieae: Colignonia (C. glomerata). Nyctagineae: Allionia (A. choisyi, A. incarnata), Boerhavia (B. cordobensis, B. diffusa, B. pulchella, B. spicata), Mirabilis (M. bracteosa, M. jalapa, M. ovata). Leucastereae: Reichenbachia (R. paraguayensis). Pisonieae: Pisonia (P. aculeata, P. zapallo), Pisoniella (P. glabrata). The pollen material was processed according to the Erdtman techniques, described and illustrated with light microscope and scanning electron microscope. The pollen grains are apolar or isopolar, radiosimetric; small to medium size, subcircular, subtriangular or cuadrangular in polar view, spheroidal, prolato-spheroidal, oblate-spheroidal or suboblate form. Tricolpate, tetracolpate, pantoporate or pantocolpoidate. Tectate perforate exine or semitectate reticulate. Variability found between genus, allows to differentiate them with the exception of Allionia and Mirabilis. In the genus represented with more than one species, Allionia, Boerhavia, Bougainvillea, and Mirabilis, it is not possible to differentiate the species from one another by the homogeneity and superposition of their characters, but it is possible in Pisonia. Keys for the identification are presented.

Resumen Farrell, E. E.; L. R. Mautino & S. S. Garralla. 2020. Morfología polínica de las Nyctaginaceae nativas de Argentina. Darwiniana, nueva serie 8(1): 292-308. Se analiza la morfología del polen de los géneros y especies de Nyctaginaceae nativas de Argentina con el fin de brindar información detallada de ellos y aportar a su identificación en polen disperso actual y fósil. La familia Nyctaginaceae en Argentina, está integrada por 8 géneros con 19 especies, incluidas en las siguientes tribus: Boungainvilleeae: Bougainvillea (B. campanulata, B.infesta, B. praecox, B. spinosa, B. stipitata). Colignonieae: Colignonia (C. glomerata). Nyctagineae: Allionia (A. choisyi, A. incarnata), Boerhavia (B. cordobensis, B. diffusa, B. pulchella, B. spicata), Mirabilis (M. bracteosa, M. jalapa, M. ovata). Leucastereae: Reichenbachia (R. paraguayensis). Pisonieae: Pisonia (P. aculeata, P. zapallo), Pisoniella (P. glabrata). El material polínico fue procesado según la técnica de Erdtman, descripto e ilustrado con imágenes obtenidas con microscopio óptico y electrónico de barrido. Como resultado se determinó que las especies argentinas de Nyctaginaceae son apolares o isopolares, radiosimétricos, de tamaño pequeño a muy grande, ámbito subcircular, subtriangular o cuadrangular, forma esferoidal, prolato esferoidal, oblato esferoidal o sub-oblata. Con aperturas simples (tricolpados, tetracolpados, pantoporados o pantocolpoidados). Exina tectada perforada o semitectada reticulada. La variabilidad encontrada a nivel de género permite diferenciarlos, para lo cual se presentan claves de identificación con la excepción de Allionia y Mirabilis. En los géneros representados con más de una especie, Allionia, Boerhavia, Bougainvillea, y Mirabilis, no pueden diferenciarse palinológicamente las especies entre sí por la homogeneidad y superposición de sus caracteres, no obstante, es posible en Pisonia.

Abstract The spore morphology and wall ultrastructure of Dryopteris filix-mas, D. patula and D. wallichiana from Argentina were studied using light microscope, scanning and transmission electron microscope. The study was carried out with herbarium material from Argentine institutions. Equatorial diameters, polar diameters and laesura length were measured. The spores are monoletes with a rugate ornamentation. The folds are short to long, inflate, irregular in shape and size, and varying from subglobose to elongate. The perispore surface is rugulate. The exospore of all the species analyzed is two-layered in section. Simple and branched channels are also present. The perispore is composed of two layers, the inner one forms the ornamentation and the outer covers all the outer and inner surfaces. Some abnormalities, such as globose, triangular or twisted spores were observed. The morphology and ultrastructure of the species are very similar. The differences observed are related to the length and thickness of the perispore folds. The characteristics of these spores would not provide relevant information to differentiate species or sections within the genus, but can provide information for phylogenetic studies as well as for alterations in the biological cycles.

O gênero Lygodium Sw. é um das poucas samambaias trepadoras no mundo. Os esporos de L. venustum Sw. e L. volubile Sw. foi estudados com microscopias de luz e eletrônicas de transmissão e varredura. Este trabalho é baseado em material de herbário. Os esporos são trilete, triangular com lados retos para convexo em vista polar. O equatorial diâmetro é 72-104 µm e o diâmetro polar é 64-84 µm. O ornamentação em L. venustum é verrucose-tuberculoso enquanto em L. volubile é verrucose-tuberculoso no proximal cara e com poucos cume no distal cara, em que um micro-ornamentação constituída por verrugas e tubérculos é observado. Um cume equatorial também está presente. O exosporo é de dois camadas, em L. venustum é liso em contraste com o exosporo ornamentado de L. volubile. O perisporo é similar nas duas espécies analisadas. Esta parede é de quatro camadas com elementos particulares dispostas radialmente na camada do meio. Nas superfícies de esporos de ambas espécies poucos spheroids é observado. Os resultados apresentados no presente estudo podem ser útil para o sistemática do gênero bem como para propósitos filogeneticos.

The genus Lygodium Sw. is one of the few climbing ferns in the world. The spores of L. venustum Sw. and L. volubile Sw. were studied using light, scanning, and transmission electron microscopy. This work is based on herbarium material. The spores are trilete, triangular, with straight to convex sides in polar view. The equatorial diameter is 72-104 µm, and the polar diameter is 64-84 µm. The ornamentation in L. venustum is verrucate-tuberculate while in L. volubile, it is verrucate-tuberculate in the proximal face but with a few ridges on the distal face, where a micro-ornamentation constituted by verrrucae and tubercles is observed. An equatorial ridge is also present. The exospore is two-layered; in L. venustum, it is smooth in contrast with the ornamented exospore of L. volubile. The perispore of the two species analyzed is similar. This wall is four-layered with particular elements arranged radially in the middle layer. On the spores surface of both species, few spheroids are observed. The results introduced in the current study may be useful for the systematics of the genus as well as for phylogenetic purposes.

The ferns and licophytes from the National Park Lago Puelo, Chubut, Argentina were studied. We registered 47 taxa with 12 of them new records for the province of Chubut and 1new to Patagonia. A high taxonom-ic diversity was observed, with about 50 % of the Patagonian fern flora represented. Some of the taxa are growing exclusively in this area and in Chile at the same latitudes. The Puelo pass, which is connect-ing Argentina and Chile, at the lowest altitude of the North- Patagonian Andes, constituted a penetrating route of Valdivian species. The presence of pasture livestock, the invasion of exotic plants and the latent fires, are the principals dangers for the survival of the Flora in this area. Therefore these areas of the Subantartic Forest merit special attention for conservation. A taxonomic key is included and a distribu-tion map that shows the areas of highest diversity of ferns and lycophytes within the national park is given. For each taxon the geographical distribution and ecology data are also given.

Se estudiaron los helechos y licofitas presentes en el Parque Nacional Lago Puelo, Chubut, Argentina. Se determinó la presencia de 47 taxa, de los cuales 12 constituyen nuevos registros para la Provincia de Chubut y 1 para la Región Patagónica. Se observó una elevada diversidad taxonómica, representando más del 50 % de la flora patagónica. Varios de los taxa crecen exclusivamente en el área y en Chile a iguales latitudes. El paso Puelo, que conecta Argentina y Chile, es el más bajo de la Cordillera de los Andes en Norpatagonia y es vía de ingreso de especies valdivianas. La presencia de animales de pastoreo, invasión de plantas exóticas y el riesgo latente de incendios, significan un peligro para la supervivencia de la flora del Parque. Todas estas características hacen que estas áreas de los Bosques Subantárticos merezcan una especial atención para su conservación. Se presentan claves para la determinación de los taxa y un mapa de ubicación de las áreas de mayor diversidad de helechos y licofitas dentro del parque. Para cada taxón registrado se da la distribución geográfica y datos ecológicos en el área de estudio.

Blechnum cordatum (Desv.) Hieron. is recorded for the first time from the Province of Salta, North-West Argentina. The species is described and illustrated and its geographical distribution in South America is also given.

Se registra por primera vez para el Noroeste de Argentina, en la Provincia de Salta, a Blechnum cordatum (Desv.) Hieron. Se describe e ilustra a la especie y se da a conocer su distribución geográfica en América del Sur.