Palynological analysis of Sphaeropteris gardneri (Cyatheaceae, Pteridophyta)

Gonzalo J Marquez,Gabriela E Giudice,Marta A Morbelli

doi:10.1590/s0001-37652010000200012

Abstract

The spore morphology and wall ultrastructure of Sphaeropteris gardneri (Hook.) R.M. Tryon from Brazil were analyzed 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 2.5microm thick, two- layered in section and single or branched channels are present. The perispore is 1.2microm 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 way. 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.

Highlights

The Sphaeropteris genus includes about 120 species (Tryon and Tryon 1982), most of them are distributed in Asia and Oceania
Spores of different specimens were studied by using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM)
The ridge margin bears conic spines 1.2-1.9μm high, which are abundant in the distal hemisphere, and are few or absent on apertural folds

Summary

Introduction

The Sphaeropteris genus includes about 120 species (Tryon and Tryon 1982), most of them are distributed in Asia and Oceania. Six species (Tryon 1971, Windisch 1977) were reported in America: S. Brunei (Christ) Tryon, S. cuatrecasasii Tryon, S. Gardneri (Hook.) Tryon, S. horrida (Liebm.) Tryon, S. Insignis (D.C. Eaton) Tryon and S. quinduiensis (Karst.) Tryon. The distinctive characteristics to differentiate this genus from the rest of the Cyatheaceae is the presence of conform scales at the bases of the petioles (Tryon 1970) and spores with echinate perispore (Korall et al 2007)

Objectives

Methods

Results

Conclusion