Resumen de Biometrics of the sporangia and spores of the "Parablechnum cordatum" complex (Blechnaceae, Polypodiopsida)

Aleksandra Patrjcia Wal, Sonia Molino de Miguel, Antonio Murciano Cespedosa , Carmen Prada Moral , José María Gabriel y Galán Moris

• español

  "Parablechnum" es el género más diverso de las Blechnaceae (ca. 65 especies), con una distribución pantropical y dos centros de diversidad, en América y en la región austro-pacífica. Las especies son dimorfas, con rizomas normalmente erguidos y escamas rizomáticas, frondas pinnadas, con hoja truncada en la base, de ápice conforme y pinnas pecioluladas. Este grupo presenta muchos problemas taxonómicos, por lo que se necesitan estudios más detallados para resolver conflictos de separación entre especies. Este trabajo trata del complejo americano de P. cordatum en el que se incluyen las especies P. cordatum, P. schiedeanum, P. chilense, P. falciforme y Blechnum varians. Se ha llevado a cabo un análisis biométrico de los esporangios y las esporas, estructuras taxonómicamente importantes en la distinción de los helechos. Los datos se sometieron a un análisis unidireccional de la varianza y a un análisis discriminante. Además, las esporas se observaron bajo un microscopio electrónico de barrido para estudiar su ornamentación. De los caracteres que hemos estudiado, el grosor del arco, el número de células en el arco, el número de células en el hipostomio y el diámetro mayor ecuatorial de la espora han apoyado estadísticamente su importancia taxonómica y, por lo tanto, son útiles para la separación de especies.

• English

  "Parablechnum" is the most diverse genus of Blechnaceae (ca. 65 species), with a pantropical distribution and two centers of diversity, in America and in the Austro-Pacific region. The species are dimorphic, with often erect rhizomes and rhizomatic scales, 1-pinnate fronds, with truncate blade at base, conform apex and stalked pinnae. This group presents many taxonomic problems, needing more detailed studies to resolve these conflicts of separation between species. This work deals with the American complex of P. cordatum in which the species P. cordatum, P. schiedeanum, P. chilense, P. falciforme and Blechnum varians are included. A biometric analysis of sporangia and spores, important taxonomic structures in the distinction of ferns, has been carried out. The data were subjected to a one-way analysis of variance and a discriminant analysis. In addition, the spores were observed under a scanning electron microscope to study their ornamentation. Of the characters we have studied thickness of the arcus, number of cells in the arcus, number of cells in the hypostome and major equatorial diameter of the spore have statisticalParablechnum is the most diverse genus of Blechnaceae (ca. 65 species), with a pantropical distribution and two centers of diversity, in America and in the Austro-Pacific region. The species are dimorphic, with often erect rhizomes and rhizomatic scales, 1-pinnate fronds, with truncate blade at base, conform apex and stalked pinnae. This group presents many taxonomic problems, needing more detailed studies to resolve these conflicts of separation between species. This work deals with the American complex of P. cordatum in which the species P. cordatum, P. schiedeanum, P. chilense, P. falciforme and Blechnum varians are included. A biometric analysis of sporangia and spores, important taxonomic structures in the distinction of ferns, has been carried out. The data were subjected to a one-way analysis of variance and a discriminant analysis. In addition, the spores were observed under a scanning electron microscope to study their ornamentation. Of the characters we have studied thickness of the arcus, number of cells in the arcus, number of cells in the hypostome and major equatorial diameter of the spore have statistically supported taxonomic significance and are therefore useful for species separation.