Comparative Anatomy of the Genus Pyrrosia Mirbel (Polypodiaceae) in Thailand

Abstract

Lamina epidermal peels and transections of leaves, stipes, rhizomes and roots of 17 Pyrrosia species in Thailand were investigated. The characteristics found to be of most use in distinguishing the species were: presence/absence of hydathodes, trichome type, stomatal type, shape and wall structure of the epidermal cells, presence/absence of hypodermis, presence/absence of sclerenchyma in the midrib and leaf margins, arrangement of the mesophyll, stipe shape in transection, distribution of sclerenchyma strands and presence/absence of sclerenchyma sheaths in the parenchyma ground tissue of the rhizomes.