Palynological analysis of Sphaeropteris gardneri (Cyatheaceae, Pteridophyta).

MARQUEZ G. J., MORBELLI M. A. Y GIUDICE G. E.

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

Elsevier

Lugar: Río de Janeiro; Año: 2010 vol. 82 p. 361 - 367

0001-3765

The spore morphology and wall ultrastructure of Sphaeropteris gardneri (Hook.) R. M. Tryon from Brazil, were analysed with LM, SEM and TEM. The spores are trilete with an ornamentation formed of short low ridges with spines in their margins. The exospore is 2.5 ìm thick, two- layered in section and single or branched channels are present. The perispore is 1.2 ìm thick and two-layered. The inner layer has three strata: the inner stratum is formed of a network of branched and fused threads, the middle stratum has threads with a radial orientation and in the outer stratum thin, dark fibres are immersed in a less dense contrasted matrix. The outer layer of the perispore is the one that forms the echinate-ridges and is constituted of threads arranged in a compact arrangement. Globules of different sizes are observed on the surface. The differences found in the perispore ornamentation and ultrastructure in Alsophila, which was previously studied, and those of Sphaeropteris show a tendency to wall complexity.