En este trabajo nos hemos ocupado previamente en hacer una breve rese&ntilde;a organogr&aacute;fica de las Pteridofitas con claves sitem&aacute;ticas desde la divisi&oacute;n hasta las especies, para abocarnos luego al estudio de estas &uacute;ltimas en particular.<br /> En cada especie, figura la sinonomia, la descripci&oacute;n original y una descripci&oacute;n ampliada con los caracteres que presentan los ejemplares consultados.<br /> A pesar de la fisonom&iacute;a que presenta la regi&oacute;n que nos ocupa, hemos podido constatar la presencia de cuatro Clases de las cinco que forman las Pteridofitas actuales distribuidas en 38 g&eacute;neros y 64 especies.<br /> Estas se hallan distribuidas principalmente en dos tipos de vegetaci&oacute;n que no son los m&aacute;s caracter&iacute;sticos de la provincia de Buenos Aires; uno de ellos, la Pluviisilvae, cuya selva en galer&iacute;a constituye una formaci&oacute;n que se extiende desde Punta Lara, hacia el norte en las m&aacute;rgenes del Paran&aacute; y Uruguay y sus afluentes e isla Mart&iacute;n Garc&iacute;a; y el otro, Rupideserta, que hallamos representado en las Sierras Bayas, Tandil y Ventana. En el resto de la provincia por el tipo de vegetaci&oacute;n y por las modificaciones que ha sufrido por la acci&oacute;n del hombre, son muy pocas las especies que hallamos.<br /> Cada especie ha sido ilustrada con dibujos y fotograf&iacute;as.In this paper we have dealt previously with a brief sketch on the organography of the Pheridophytes with systematic Keys from Division up to species, to settle down after on the study of the latter in particular.<br /> With each species is the synonym, original description and an enlarged description with the characters that are present in the specimens consulted.<br /> In spite of the physiography of the region, that we are dealing with, we have been able establish the presence of four classes of the five that form the actual Pteridophytes, distributed in 38 genera and 64 especies.<br /> There are distributed mainly in two types of vegetation, which are the most characteristic in the province of Buenos Aires: one of these is Pluviisilvae, its forest in gallery presents a formation that ranges from Punta Lara toward the north on the margins of the Paran&aacute; River and Uruguay River and its tributaries and also on the Isle of Mart&iacute;n Garcia; the other formation is Rupideserta, which is represented in the Sierras Bayas, Tandil and Ventana.<br /> The species we found in the remaining part of the province, were very few on account of the vegetation which is different and also because of the modifications that this suffered due to action of man.<br /> Each species has been illustrated with drawings and photographs.