A. C. Seward,
Fossil plants, Vol. 2: A text-book for students of botany and geology
(1910)
“ The lamina becomes narrower towards the base, which is either cuneate or in some cases slightly auriculate (fig. 345) .As I have elsewhere pointed out [1344] , the presence or absence of a midrib is not in itself a character of real taxonomic importance. In the recent fern Scolopendrium vulgare the frond has a prominent midrib, while in S. nigripes there is no median rib. Mr Arber has expressed the opinion that “it is extremely doubtful whether the genus Gangamopteris should not be merged in Glossopteris [1345] .” ”
