Record of Thelypteris decurtata (Link) de la Sota ssp. platensis (Weath.) de la Sota in Punta Lara (Buenos Aires) Natural Reserve: a contribution to the conservation of native ferns with restricted distribution

Se da a conocer el registro de Thelypteris decurtata ssp. platensis en la Reserva Natural Punta Lara (Provincia de Buenos Aires). Este helecho tiene una distribución restringida, es endémico de Argentina y Uruguay y se lo encuentra asociado a cursos de agua o zonas inundables. Hasta el momento se contaba con citas de colecciones de más de 50 años y en distintas zonas cercanas a la Reserva. Se destaca la importancia de la selva marginal, que representa el extremo austral de la selva en galería asociada a los ríos mesopotámicos y que constituye un refugio natural para la flora nativa. Se describe e ilustra el material registrado y se proponen estrategias para su conservación.This paper discloses the presence of Thelypteris decurtata ssp. platensis in Punta Lara (Buenos Aires) Natural Reserve. This fern has a restricted distribution since it is endemic of Argentina and Uruguay, and grows near watercourses and in flood zones. So far there were collections dating more than 50 years, in different areas around the Reserve. We highlights the importance of the marginal forest, which represents the southern end of the gallery forest associated with the mesopotamian rivers, and it is a natural haven for native flora stands. Description and illustrations of the registered taxon are given and strategies for its conservation are proposed.Fil: Giudice, Gabriela Elena. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Ramos Giacosa, Juan Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luna, María Luján. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

The Ferns of the Calilegua National Park: a look through their spores. Part I

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.Fil: Gorrer, Daniel Alejandro. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; ArgentinaFil: Ramos Giacosa, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; ArgentinaFil: Lupo, Liliana Concepcion. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; Argentin

Spore wall ultrastructure in Anogramma species (Pteridaceae) from Argentina

The sporoderm ultrastructure of Anogramma Link species, which grow in Argentina, was studied using scanning and transmission electron microscopy. The species A. chaerophylla (Desv.) Link and A. lorentzii (Hieron.) Diels were studied with TEM for the first time. The spores of both species have a sculptured, apparently two-layered exospore. The perispore is uniformly thickened on the whole surface: in A. chaerophylla it is three-layered, while, in A. lorentzii it is single-layered with a complex structure. Spherules are present on the perispore surface or incorporated into the structure of A. chaerophylla while, globules exist on and within the perispore in A. lorentzii. The sporoderm ultrastructure in these two species was compared with other cingulate genera within the Pteridaceae. The characteristics found in this work, with respect to spore wall structure and general morphology, suggest that these characters may differentiate species within genus.Facultad de Ciencias Naturales y Muse

Spore wall ultrastructure in Anogramma species (Pteridaceae) from Argentina

The sporoderm ultrastructure of Anogramma Link species, which grow in Argentina, was studied using scanning and transmission electron microscopy. The species A. chaerophylla (Desv.) Link and A. lorentzii (Hieron.) Diels were studied with TEM for the first time. The spores of both species have a sculptured, apparently two-layered exospore. The perispore is uniformly thickened on the whole surface: in A. chaerophylla it is three-layered, while, in A. lorentzii it is single-layered with a complex structure. Spherules are present on the perispore surface or incorporated into the structure of A. chaerophylla while, globules exist on and within the perispore in A. lorentzii. The sporoderm ultrastructure in these two species was compared with other cingulate genera within the Pteridaceae. The characteristics found in this work, with respect to spore wall structure and general morphology, suggest that these characters may differentiate species within genus.Facultad de Ciencias Naturales y Muse

Anatomical Features of the Tubercle and Young Sporophyte of the Annual Fern <i>Anogramma chaerophylla</i> Growing in the Punta Lara Natural Reserve (Buenos Aires, Argentina)

The fern genus Anogramma is characterized by the presence of annual sporophytes and tubercles that persist through dry periods. Tubercles may host embryos that develop when climatic conditions are more favorable. As information on the structure of the tubercle and sporophyte of Anogramma chaerophylla is incomplete, the objective of this work was to analyze anatomical characteristics during development and deepen knowledge of the adaptive strategies of this species. Spores were grown in-vitro and different stages of tubercle development and embryonic sporophytes were fixed in FAA, embedded in Paraplast and analyzed using light microscopy. Initially, the green gametophyte developed antheridia and archegonia in its thickened portion, where later bisexual tubercles differentiated. Embryos developed only from the archegonia located in the tubercles, with one embryo developing per tubercule. During sporophyte growth the reserves accumulated in the tubercle were consumed. Oversized cells were observed at the junction between the green gametophyte and the tubercle, suggesting a possible role in translocation of substances. The young sporophyte consisted of a short shoot and a prominent foot. The placenta comprised the foot cells and the adjacent tubercle cells. The first leaves protruded soon and developed early as photosynthetic organs. Sporophytes remained attached to the tubercles until advanced stages of development. Vegetative propagation was documented in smaller tubercles that did not develop gametangia. Because few sporophytes were observed in vivo, it is likely that natural populations are maintained through vegetative propagation of the gametophyte until favorable conditions encourage development of sporophytes.Facultad de Ciencias Naturales y Muse

El cultivo in vitro de esporas y los aspectos reproductivos del helecho anual Anogramma chaerophylla (Pteridaceae)

Anogramma chaerophylla pertenece a un género de helechos con esporofitos anuales y gametofitos potencialmente perennes. En el área de estudio, la Reserva Natural Punta Lara, la vegetación crece bajo estrés debido principalmente a la contaminación y la invasión de especies exóticas. Como parte de un proyecto de conservación de helechos que habitan en la provincia de Buenos Aires, los objetivos del trabajo fueron evaluar en Anogramma chaerophylla las condiciones para la germinación de esporas in-vitro y analizar las distintas etapas de su ciclo reproductivo. Las esporas fueron desinfectadas en solución 10 % de NaCIO durante distintos tiempos y sembradas luego en medio de cultivo Murashige – Skoog, sin agregado de sacarosa. Las cápsulas se incubaron con un fotoperíodo de 12 h luz/oscuridad y una temperatura de 22 (± 2) °C. A las dos semanas germinaron el 80% de las esporas. El patrón de germinación fue tipo Vittaria y el desarrollo del protalo tipo Ceratopteris. Los gametangios aparecieron primero en la región engrosada del protalo donde posteriormente se originaron los tubérculos bisexuales. Los esporofitos se desarrollaron solo en asociación con los tubérculos. Durante su cultivo en macetas, éstos dieron origen a una segunda generación de protalos. Nuestros resultados demuestran que la técnica de cultivo in vitro es apropiada para la propagación de Anogramma chaerophylla y como estrategia para su conservación ex-situ.Anogramma chaerophylla belongs to a fern genus with annual sporophytes and potentially perennating gametophytes. In the studied area, Natural Reserve Punta Lara, the plants grow stressed mainly by pollution and the invasion of exotic species. As a part of a project on conservation of ferns inhabiting Buenos Aires province, the objectives of this work were to evaluate in Anogramma chaerophylla the conditions for in-vitro spore germination and to analyse the different stages of its reproductive cycle. Spores were sterilized in an aqueous solution 10 % of NaCIO during different times and then sown in Petri dishes with Murashige & Skoog medium, without the addition of sucrose. The dishes were kept under laboratory conditions, at 12 h light/ darkness photoperiod and a temperature of 22 (± 2) °C. After two weeks, the percentage of germination was 80%. The spore germination pattern corresponds to the Vittaria type and the prothallus development was Ceratopteris type. Gametangia developed first in the bended thalloid region of the prothallus and then bisexual tubercles originated near this zone. The sporophytes developed only in association with the tubercles. During culture in plastic pots the sporophytes gave origin to a second generation of prothalli. Our preliminary findings demonstrate that the in vitro culture technique is suitable for A. chaerophylla propagation as a strategy for ex-situ conservation.Fil: Luna, María Luján. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; ArgentinaFil: Yañez, Agustina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Ramos Giacosa, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; ArgentinaFil: Gorrer, Daniel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; ArgentinaFil: Berrueta, Pedro Cayetano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; ArgentinaFil: Giudice, Gabriela Elena. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Morfología Vegetal; Argentin

Desarrollo del gametofito y conservación de Ctenitis submarginalis (Dryopteridaceae) en la provincia de Buenos Aires, Argentina

Se estudió la germinación de las esporas y el desarrollo del gametofito de Ctenitis submarginalis de la Reserva Natural Punta Lara, provincia de Buenos Aires como contribución a la conservación de la especie en ésta área protegida. Las esporas colectadas de las poblaciones naturales fueron sembradas en medio de Dyer y la germinación se produjo a los seis días, con un porcentaje de germinación del 88 % a los 15 días después de la siembra. La germinación es del tipo Vittaria y el desarrollo del gametofito tipo Aspidium. El gametofito de Ctenitis submarginalis es cordado, con una profunda escotadura y alas simétricas bien desarrolladas. Los gametangios aparecen a los 50 días después de la siembra. El esporofito emerge a los 190 días después de la siembra y dos tipos diferentes de pelos se observaron en la primera lámina. La germinación in-vitro a través de esporas es un método exitoso para la obtención de numerosos esporofitos de Ctenitis submarginalis. Los esporofitos obtenidos fueron gradualmente aclimatados, transplantados a su hábitat natural en la reserva y serán periódicamente monitoreados para contribuir a la conservación de la especie.The spore germination and gametophyte development of Ctenitis submarginalis from Punta Lara Natural Reserve, Buenos Aires province were studied as a contribution to the conservation of the species in this protected area. Spores collected from natural populations were sowing in Dyer medium and germinated in six day with a percentaje of 88 % fifteen days after sowing. The germination is Vittaria type and the gametophyte development is Aspidium type. The gametophyte of Ctenitis submarginalis is cordate, with a deep notch and well developed and symmetric wings. The gametangia appear 50 days after sowing. The sporophyte emerges 190 days after sowing and two different hairs were observed in the first lamina. The in-vitro spore germination is a successful method for obtaining numerous sporophytes of Ctenitis submarginalis. The sporophytes obtained were gradually acclimated, transplanted to its natural habitat in the reserve and will be monitored frequently to contribute to the conservation of the species.Facultad de Ciencias Naturales y Muse

Desarrollo del gametofito y conservación de Ctenitis submarginalis (Dryopteridaceae) en la provincia de Buenos Aires, Argentina

Se estudió la germinación de las esporas y el desarrollo del gametofito de Ctenitis submarginalis de la Reserva Natural Punta Lara, provincia de Buenos Aires como contribución a la conservación de la especie en ésta área protegida. Las esporas colectadas de las poblaciones naturales fueron sembradas en medio de Dyer y la germinación se produjo a los seis días, con un porcentaje de germinación del 88 % a los 15 días después de la siembra. La germinación es del tipo Vittaria y el desarrollo del gametofito tipo Aspidium. El gametofito de Ctenitis submarginalis es cordado, con una profunda escotadura y alas simétricas bien desarrolladas. Los gametangios aparecen a los 50 días después de la siembra. El esporofito emerge a los 190 días después de la siembra y dos tipos diferentes de pelos se observaron en la primera lámina. La germinación in-vitro a través de esporas es un método exitoso para la obtención de numerosos esporofitos de Ctenitis submarginalis. Los esporofitos obtenidos fueron gradualmente aclimatados, transplantados a su hábitat natural en la reserva y serán periódicamente monitoreados para contribuir a la conservación de la especie.The spore germination and gametophyte development of Ctenitis submarginalis from Punta Lara Natural Reserve, Buenos Aires province were studied as a contribution to the conservation of the species in this protected area. Spores collected from natural populations were sowing in Dyer medium and germinated in six day with a percentaje of 88 % fifteen days after sowing. The germination is Vittaria type and the gametophyte development is Aspidium type. The gametophyte of Ctenitis submarginalis is cordate, with a deep notch and well developed and symmetric wings. The gametangia appear 50 days after sowing. The sporophyte emerges 190 days after sowing and two different hairs were observed in the first lamina. The in-vitro spore germination is a successful method for obtaining numerous sporophytes of Ctenitis submarginalis. The sporophytes obtained were gradually acclimated, transplanted to its natural habitat in the reserve and will be monitored frequently to contribute to the conservation of the species.Facultad de Ciencias Naturales y Muse

Comparative palynological analysis of Lygodium venustum Sw. and L. volubile Sw. (Lygodiaceae)

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.Facultad de Ciencias Naturales y Muse

Spore wall ultrastructure in Anogramma species (Pteridaceae) from Argentina

The sporoderm ultrastructure of Anogramma Link species, which grow in Argentina, was studied using scanning and transmission electron microscopy. The species A. chaerophylla (Desv.) Link and A. lorentzii (Hieron.) Diels were studied with TEM for the first time. The spores of both species have a sculptured, apparently two-layered exospore. The perispore is uniformly thickened on the whole surface: in A. chaerophylla it is three-layered, while, in A. lorentzii it is single-layered with a complex structure. Spherules are present on the perispore surface or incorporated into the structure of A. chaerophylla while, globules exist on and within the perispore in A. lorentzii. The sporoderm ultrastructure in these two species was compared with other cingulate genera within the Pteridaceae. The characteristics found in this work, with respect to spore wall structure and general morphology, suggest that these characters may differentiate species within genus.Facultad de Ciencias Naturales y Muse