Helechos

Se describe y se ilustra Pecluma sanctae-mariae, una nueva especie de los Andes de Colombia. Se cambia el estatus de Pecluma ptilota var. bourgeauana y se designa su lectotipo. A new species, Pecluma sanctae-mariae, is described and illustrated from the Andes of Colombia. The status of Pecluma ptilota var. bourgeauana is changed and its lectotype is designated.

AbsTrACT The spore morphology and wall ultrastructure of Microlepia speluncae and Pteridium arachnoideum from the Paranaense Province were analyzed with LM, SEM and TEM and a comparative analysis was carried out. In both species the spores are covered by a three-dimensional network of threads branched and fused, tangentially arranged to the surface, and some free-end threads are also seen. The species were differentiated by morphology and the frequency of threads fusion and the networks distribution on the surface of the spores. In both species the exospore is two-layered in section, both layers are traversed by single or branched channels. The perispore is three-layered in section: the inner layer is adhered to the exospore, the middle layer is formed of a three-dimensional network of threads and the outer layer is discontinuous. The perispore ultrastructure of Microlepia speluncae was interpreted as formed of helical subunits displayed around a central channel. The spore morphology and perispore ultrastructure allow differentiating Microlepia from Pteridium but also to the other Dennstaedtiaceae genera that grow in the Paranaense Province. The results obtained allow establishing relationships that let us recognize different groups and gave a new reference to get a better knowledge of the family.

Palacios-Rios, M. 1994. Las pteridofitas de Veracruz: Biodiversidad y problemática de su conservación. In: G. Castillo & M.T. Mejía (eds.) Problemática Ambiental en el Estado de Veracruz. Universidad Veracruzana-Colegio Profesional de Biólogos del Estado de Veracruz, A.C. Publicaciones de la Universidad Veracruzana. Xalapa, Ver. Recursos Vegetales 89-102.

Se presenta el catálogo comentado de las especies colombianas de Pecluma M.G. Price (Polypodiaceae). Se analiza la variabilidad morfológica del género en Colombia, se presentan comentarios para facilitar su reconocimiento y claves para las especies y variedades. Para cada taxón se presentan los datos del protólogo, sus tipos nomenclaturales y sinónimos, datos del hábitat y distribución geográfica, comentarios, ejemplares de referencia, ilustraciones y mapas de distribución en Colombia. También, se explica la etimología de la mayoría de los epítetos. Como resultado de esta revisión se transfiere P. absidata a la sinonimia de P. curvans; se registran por primera vez para Colombia P. pastazensis, P. pilosa y P. robusta, y se redescubre P. paradiseae en el país.

This work presents a commented checklist of the Colombian species of Pecluma M.G. Price (Polypodiaceae). The morphological variability of the genus in Colombia is analized; comments for its easy recognition and keys for the species and varieties are presented. For each taxon, the original publication, nomenclatural types, synonyms, habitat, geographic distribution, pertinent comments, reference specimens, figures and maps are presented. In addition, the etymologies of most of the epithets are explained. As a result of this revision P. absidata was transferred to the synonymy of P. curvans; the species P. pastazensis, P. pilosa, and P. robusta were recorded for the first time to Colombia, and P. paradiseae is rediscovered in the country.

En este trabajo se cita por primera vez a Megalastrum substrigosum para Argentina, en el departamento de San Pedro, provincia de Misiones. Se presenta una descripción general de la especie, el mapa de su distribución en el país e ilustraciones sobre los caracteres más importantes para su determinación. Se incluye una clave dicotómica para diferenciar las tres especies presentes en Misiones.

Volumen especial editado en Acta Botanica Malacitana
http://www.revistas.uma.es/index.php/abm/issue/view/217/showToc
Monografía que incluye una veintena de artículos pteridólogicos , en la que se ofrece una perspectiva de los estudios actuales sobre los helechos y sus aliados, con contribuciones en distintas disciplinas y en donde se ofrecen novedades taxonómicas y corológicas.

The spore morphology and wall ultrastructure of Microlepia speluncae and Pteridium arachnoideum from the Paranaense Province were analyzed with LM, SEM and TEM and a comparative analysis was carried out. In both species the spores are covered by a three-dimensional network of threads branched and fused, tangentially arranged to the surface, and some free-end threads are also seen. The species were differentiated by morphology and the frequency of threads fusion and the networks distribution on the surface of the spores. In both species the exospore is two-layered in section, both layers are traversed by single or branched channels. The perispore is three-layered in section: the inner layer is adhered to the exospore, the middle layer is formed of a three-dimensional network of threads and the outer layer is discontinuous. The perispore ultrastructure of Microlepia speluncae was interpreted as formed of helical subunits displayed around a central channel. The spore morphology and per...

Mehltreter , K. & M. Palacios-Rios. 2002. The flora pteridológica latinoamericana database and its use for assessing pteridophyte diversity and biogeography. Symposium Fern flora worlwide: threats and responses. University of Surrey, Guildford, UK. In: Proceedings of the International Symposium. The Fern Gazette. 16 (6, 7, 8) 23-26 julio. PP 398-403.

Palacios-Rios, M. 1992. Cultivation of tropical pteridophytes in the Jardín Botánico "Francisco J. Clavijero" of Xalapa, Veracruz, México. In: B.A. Thomas & J. Ide (eds.) Fern Horticulture: past, present and future perspectives. Fern Gazette-Intercept, Andover. 263-266.