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STRUCTURE AND AFFINITIES OF PROTOSTIGMARIA EGGERTIANA
Author(s) -
Jennings James R.,
Karrfalt Eric E.,
Rothwell Gar W.
Publication year - 1983
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1983.tb07894.x
Subject(s) - biology , affinities , extant taxon , botany , paleontology , evolutionary biology , biochemistry
Investigation of new, more or less complete specimens of Protostigmaria eggertiana reveals that it is a large, multilobed rooting structure produced at the base of a small arborescent lycopod. The trunk bears scars marking the point of attachment of leaves, and can be compared to the stem of Lepidodendropsis . In the largest specimens the root‐bearing base is divided into about 13 lobes. In smaller, presumably younger specimens, fewer lobes are present. The roots are arranged on the lobes in series and orthostichies comparable to those of Isoetes . New observations on five‐ and six‐lobed Isoetes plants reveal a closer correspondence between Protostigmaria and Isoetes than previously recognized; and support suspected homologies among many fossil and extant lycopsid rooting structures.