The equisetales are at present a well-defined group; even in the rich Palaeozoic floras the habit, anatomy and reproductive characters usually render the members of this class unmistakable, in spite of the great development and stature which they then attained.
"Darwin and Modern Science"
A.C. Seward and Others
In this genus especially, but also in the entire group, there is an evident relation to the equisetales; hence it is of great interest that Nathorst has described, from the Devonian of Bear Island in the Arctic regions, a new genus Pseudobornia, consisting of large plants, remarkable for their highly compound leaves which, when found detached, were taken for the fronds of a Fern.
"Darwin and Modern Science"
A.C. Seward and Others
The equisetales likewise have a long history, and manifestly attained their greatest development in Palaeozoic times.
"Darwin and Modern Science"
A.C. Seward and Others