News | Published:

On the Tree-Ferns of the Coal Measures, and their Affinities with Existing Forms

Nature volume 6, pages 486487 | Download Citation

Subjects

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.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

About this article

Publication history

Published

DOI

https://doi.org/10.1038/006486a0

Authors

    Comments

    By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

    Newsletter Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing