Contributions to the bryological flora of the tropical and subtropical forests from the Argentina (Bryophyta, Musci).

The authors present here a list of 32 mosses belonging to 15 families: Brachytheciaceae, Cryphaeaceae, Entodontaceae, Hedwigiaceae, Hypnaceae, Leptodontaceae, Meteoriaceae, Neckeraceae, Pilotrichaceae, Polytrichaceae, Pterobryaceae, Racopilaceae, Rigodiaceae, Stereophyllaceae, and Trachypodaceae, all collected in the mountainous forests of the Yungas of the NW of the Argentina (Jujuy, Salta, Catamarca and Tucumán provinces), and also in the rainforests from the NE of the country (Misiones province). Eight species: Atrichum polycarpum, Chrysohypnum elegantulum, Pilosium chlorophyllum, Pilotrichella flexilis, Porotrichodendron lindigii, Pseudotrachypus martinicensis, Steerecleus scariosus, and Thamnobryum fasciculatum are new records for the bryologic flora from Argentina. Braunia imberbis and Squamidium brasiliense are two new records for the bryophytic flora of the Catamarca province; Porotrichodendron superbum is new for the Salta province, while Forsstroemia coronata is the first record for the Catamarca and Jujuy provinces. Aerolindigia capillacea, Braunia reflexifolia, Chryso-hypnum diminutivum, Meteorium deppei and Meteoridium remotifolium are five new citations for the Jujuy province, and Schoenobryum concavifolium is new for the bryophytic flora of the Misiones province. Many studied species occur more frequently in the Yungas than in the NE rainforests; others show separated distribution but live in both areas, the Yungas and Paranaense area, and others are more or less restricted to the Paranaense rainforest of the NE of Argentina. The taxonomy of species is updated, and comments are included on bibliographical precedents, ecology and chorology of each taxon.

Floristic notes of Sierra del Rincón Biosphere Reserve (Spain, Madrid province)

New records of vascular plants from Sierra del Rincón Biosphere Reserve and surroundings (Spain, Madrid province) are provided. It is noteworthy the presence of atlantic flora in this continental area and the different shrubby communities in different sectors with different litology: in areas with gneiss they are dominated by leguminous genisteae; where it is schistous, shale or quartzite they are heathlands.

Paul Karl Feyerabend Las proyecciones de la proliferación teórica en la relación ciencia-metafísica

La doctrina de la Proliferación teórica de Paul Karl Feyerabend ha sido interpretada por sus especialistas como un intento de salvaguardar el ideal del progreso científico. Aunque tales estudios hacen justicia, en parte, a la intencionalidad de nuestro filósofo no explicitan la crítica fundamental que implica para Feyerabend el pluralismo teórico. La proliferación teórica constituye en sí misma una reductio ad absurdum de los distintos intentos del positivismo lógico y del racionalismo crítico por definir la ciencia a expensas de lo metafísico. Este artículo presenta la proliferación teórica como una reivindicación del papel positivo que ocupa la metafísica en el quehacer científico. Se consigna la defensa que hace Feyerabend de la metafísica en cuanto que ésta constituye la posibilidad de superar el conservadurismo conceptual, aumentar de contenido empírico de la ciencia y recuperar el valor descriptivo de las teorías científicas.