A Comparative Study of the Foliar Anatomy of Lycopodium Species

Abstract

A comparative study of the leaves of 31 species of Lycopodium was made. The pattern of tracheids varies with the species. Usually they exhibit annular, helical, reticulate, modified or transition forms; none of the species have advanced phylogenetically beyond the scalariform tracheid stage. Mucilage canals have been found in four species. Tracheids are enclosed by a few to several layers of oblique ended, elongated parenchyma cells in most species, but an endodermis is absent. Vascular bundles are encircled by fiber cells in three species. The mesophyll of most species consists of identically shaped cells, although palisade‐like tissue has been observed in a few species. The epidermal cells vary from elongated to isodiametric and have either undulated or smooth anticlinal walls, which are deeply pitted in some species. The outer epidermal walls are usually thick and heavily cutinized. Stomates are distributed on both surfaces in 18 species, on the abaxial surface in 11 species, and on the adaxial side in only two species. Most stomates are practically isodiametric in surface view, broader than epidermal cells, usually parallel to the vein, and at the same level as the adjacent epidermal cell. A typical guard cell has a prominent outer ledge and a less developed inner ledge of cutin in most species. Six groupings are suggested, based on similarity of leaf structure and the known chromosome numbers.

Morfologia externa e interna das folhas vegetativas, esporofilos e esporângios de espécies de Huperzia Bernh. (Lycopodiaceae - Pteridophyta) do Brasil

“…As exsicatas estão indicadas, abaixo, dentro de cada grupo de espécies. Para a reidratação do material herborizado, fragmentos de caule portando folhas e esporângios foram colocados em água destilada com algumas gotas de glicerina e mantidos em estufa a 58 °C, por aproximadamente 48 h (Chu 1974 Para o estudo anatômico, folhas vegetativas, esporofilos e esporângios -localizados nas regiões apical, mediana e basal do caule -foram diafanizados, seccionados (à mão livre e em micrótomo de rotação) e macerados. Para a diafanização, utilizou-se hipoclorito de sódio comercial 50% por duas horas e o método de Strittmatter (1973), modificando-se o tempo da fervura em álcool 96 °GL e em solução de álcool 96 °GL e NaOH 5%.…”

Development and Distribution of Mucilage Canals in Lycopodium

“…This layer of cells is quite thin in diameter. Chu (1974) states that this separating layer was often entirely absent. However, I found no evidence to support his conclusion.…”

“…L. dichotomum X Sykes, 1908 L. [ontanalis x Sykes, 1908 L. lucidulum x L. nummularijolium x Jones, 1905;Sykes, 1908 L. pithyoides x L. phlegmaria x Jones, 1905;Sykes, 1908 , 1974;Eiger, 1956;Lloyd and Underwood, 1900 L. appressum x Eiger, 1956;Lloyd andUnderwood, 1900 L. cernuum x Bierhorst, 1971;Chu, 1974;Hill, 1906;Smith, 1955L. inundatum x Chu, 1974G1iick, 1895;Hegelmaier, 1872;Lloyd and Underwood, 1900;Sykes, 1908Sykes, , 1909…”