Se presenta la revisión del género Hymenophyllum (Hymenophyllaceae) para la región templada de Argentina y Chile. El estudio contiene una clave para las 22 especies reconocidas dentro de la actual definición del género, incluye descripciones enmendadas, ilustraciones y mapas de distribución geográfica. Se establecen los nombres aceptados y sinónimos nuevos de los taxones, incluyendo a Serpyllopsis caespitosa e Hymenoglossum cruentum dentro del género Hymenophyllum. Se designaron lectotipos para 21 nombres. Se incluye una filogenia, basada en secuencias del gen de cloroplasto rbcL, en donde se corroboran las posiciones de especies no muestreadas hasta el momento en los subgéneros correspondientes.

No abstract

Los atlas biogeográficos son la síntesis de patrones de distribución representada por trazos individuales, generalizados, nodos, áreas de endemismo y cladogramas de áreas, y a partir de ellos es posible establecer áreas prioritarias a conservar. Los helechos son indicadores de calidad de los hábitats y su falta de relaciones coevolutivas con vectores bióticos, así como su monofilia y estabilidad morfológica los hacen apropiados para establecer patrones biogeográficos. Nuestro objetivo fue aplicar análisis de trazos y parsimonia de endemismos a la flora de helechos de las Sierras de Córdoba (77 taxones) para contribuir a la elaboración del Atlas Biogeográfico centro-argentino. El patrón distribucional encontrado muestra las estrechas relaciones de estos helechos con las floras de las Sierras Subandinas; los Andes del Norte, los sistemas serranos de Buenos Aires y el sur de Brasil, correspondiéndose con el Arco Peripampásico Serrano. La protección de un espacio geográfico rico y complejo, con taxones endémicos y de distribución más amplia, garantiza preservar las condiciones en las que los taxones se desenvuelven. En este sentido, las sierras de Córdoba son un área prioritaria para conservar, porque constituyen un nodo o área biogeográficamente compleja, con una riqueza apreciable en especies de helechos y orígenes históricos, siendo un centro de convergencia biótica.

The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.

The cosmopolitan species Hymenophyllum tunbrigense was traditionally represented in southern South America by two allopatric varieties: H. tunbrigense var. tunbrigense in the Andean Patagonian forests of Argentina and Chile, and H. tunbrigense var. cordobense, an endemic taxon restricted to the mountain system of central and north-western Argentina. Given the diagnosable differences between these two taxa, and between these taxa and the European and African entity, based on morphological, anatomical, molecular, ecological and distributional evidence, we exclude H. tunbrigense for Southern Cone, propose to revalidate the name Hymenophyllum asperulum for the species present in the Magellanic and Valdivian forests and elevate H. tunbrigense var. cordobense to species rank. We consider these two taxa as endemic species, closely related to the widespread H. tunbrigense. We also cite Hymenophyllum cordobense for first time for the flora of Bolivia.

ResumenHymenophyllaceae constituye uno de los linajes más tempranamente divergente dentro de los helechos, habitan lugares hiperhúmedos y su aparición se ha datado en el cretácico temprano, previa a la ruptura de Gondwana; estas características determinan que sean especialmente útiles para establecer patrones biogeográficos. En este trabajo se discuten la diversidad de la familia Hymenophyllaceae en las Yungas meridionales y sus vinculaciones biogeográficas, mediante un análisis panbiogeográfico. Se han encontrado nueve especies, comprendidas en cuatro géneros: Crepidomanes, Didymoglossum, Hymenophyllum y Polyphlebium; Crepidomanes pyxidiferum constituye una novedad florística a nivel genérico para Argentina. Se brindan una clave para todos los géneros de Hymenophyllaceae presentes en Argentina, así como claves entre todas las especies presentes en las Yungas, que además son descriptas e ilustradas. Palabras-clave: Crepidomanes, Dydimoglossum, Hymenophyllum, Polyphlebium, biogeografía. AbstractHymenophyllaceae represents a very ancient lineage of ferns that inhabit hyperhumid places and appeared in the Early Cretaceous, prior to the breakup of Gondwana; these features make Hymenophyllaceae especially useful to establish biogeographic patterns. The diversity of Hymenophyllaceae in meridional Yungas and their biogeographical relationships, employing a panbiogeographic analysis, are discussed. Nine species in four genera: Crepidomanes, Didymoglossum, Hymenophyllum and Polyphlebium were found; Crepidomanes pyxidiferum constitutes a novelty of generic level for Argentina. A key to all genera of Hymenophyllaceae present in Argentina are provided as well as keys for all species inhabiting the Yungas, which are also described and illustrated. The generalized track shows close relationships among the Argentine Yungas with the North Andes and the Parana dominion, overcoming the arid barrier represented by the Chacoan dominion. Furthermore, the South American Transition Zone constitutes a current barrier between the neotropical and the south-andean Hymenophyllaceae pteridofloras.

of sporoderm structure were found: C. squamosa group, and a typically cheilanthoid structure with diverse sculptures in the rest of the species of Cheilanthes, i.e., C. bonariensis, C. buchtienii, C. cf. cucullans. C. obducta, and C. volcanensis. Sporophytic features such as hairs with "tongue and groove" wall cells and dixylic vascular strands are also mentioned in C. obducta. Similar spore characteristics are correlated with sporophyte morphology in some of the recognized groups. Spore-size differences, abnormalities in spore type, abortion and number of spores per sporangium (16, 32) suggest polyploidy and/or apogamy in some specimens of C. buchtienii, C. obducta, and C. squamosa, and in all The present paper is the second in a series of studies on cheilanthoid ferns prehminary to an ongoing project, "Atlas of Spores of Pteridophyta of Northwestern Argentina" (Morbelli, in prep.). Perispore structure and stratification offer some interesting substructures and variations. Previous papers (Ranker, 1989; Tryon and Lugardon, 1991) have shown that detailed analysis of the exospore and perispore can provide valuable information in cheilanthoid ferns. The aim of these papers is to characterize each species of the region from the palynological point of view and to assess whether spore morphology is useful in the systematics of the group. When necessary, sporophytic features are included for comparative analysis of species groups. MethodsIn the first part of this study (Morbelli and Michelena, 1989), the following

No abstract