Abstract
L INDLEY and Hutton describe two species of tree-ferns from the Coal Measures, both from the Bath Coal-field. I have been able to add eight species hitherto undescribed, chiefly through the assistance of Mr. J. M'Murtrie, of Radstock. These belong to three groups, which are remarkably distinguished by peculiarities in the structure of the stems. Two of the groups belong to living forms, while the third is extinct, being confined to Palaeozoic formations. Caulopteris and Tubicaulis belong to the same type as the living ferns which possess stems, including under this term the humble stems (falsely called rhizomes) of many of our British species, as well as the arborescent ferns of warmer regions; and excluding the rhizomatous forms like Pteris, Polypodium, and Hymenophyllum. In all these stems we have a central medulla, surrounded by a continuous vascular cylinder penetrated regularly by meshes, from the margins of which the vascular bundle or bundles to the fronds are given off, and through which the parenchyma of the medulla is continuous with that of the stipes. In most tree-ferns the medullary axis is larger, and the bases of the stipes decay down to the circumference of the stem, but in Osmunda the persistent bases of the stipes permanently clothe the small vascular cylinder which encloses a slender pith. To this latter form belongs the stipe with a dumbell-shaped vascular bundle, separate specimens of which I have obtained from the Coal Measures. These have been described both on the Continent and in this country, under the name of Zygopteris, but they belong to Cotta's genus Tubicaulis; and they are very closely allied to a group of fern stems which I have already placed together under the name of Chelepteris. The stem structure of the common tree-fern is represented by the genus Caulopteris, of which I have six species of carboniferous age.
Article PDF
Rights and permissions
About this article
Cite this article
On the Tree-Ferns of the Coal Measures, and their Affinities with Existing Forms . Nature 6, 486–487 (1872). https://doi.org/10.1038/006486a0
Issue Date:
DOI: https://doi.org/10.1038/006486a0