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Psilophyton is a genus of extinct vascular plants. Described in 1859, it was one of the first fossil plants to be found which was of Devonian age (about 420 to 360 million years ago ). Specimens have been found in northern Maine , USA; Gaspé Bay , Quebec and New Brunswick , Canada; the Czech Republic ; and Yunnan , China.
The class was established in 1917, under the name Psilophyta, with only three genera (Rhynia, Horneophyton and Psilophyton) [1] for a group of fossil plants from the Upper Silurian and Devonian periods which lack true roots and leaves, but have a vascular system within a branching cylindrical stem.
Psilotum is a genus of fern-like vascular plants.It is one of two genera in the family Psilotaceae commonly known as whisk ferns, the other being Tmesipteris.Plants in these two genera were once thought to be descended from the earliest surviving vascular plants, but more recent phylogenies place them as basal ferns, as a sister group to Ophioglossales.
Trimerophytopsida (or Trimeropsida) is a class of early vascular plants from the Devonian, informally called trimerophytes.It contains genera such as Psilophyton.This group is probably paraphyletic, and is believed to be the ancestral group from which both the ferns and seed plants evolved.
The first species of this genus (Sawdonia ornata) was described in 1859 by Sir J. William Dawson and, was originally attributed to the genus Psilophyton. He named this plant Psilophyton princeps. In 1971 Francis Hueber proposed a new genus for this species due to its "Divergent technical characters from the generic description for Psilophyton."
After Gwynne-Vaughan's death in 1915 [4] he studied preserved plant remnants in Aberdeen, making great insights into the nature of Psilophyton, which until then had been neglected. [3] In 1900 he was awarded a Doctor of Science degree by the University of Glasgow, and when the Barker chair of cryptogamic botany was created at the University of ...
Rhynia is a single-species genus of Devonian vascular plants. Rhynia gwynne-vaughanii was the sporophyte [2] generation of a vascular, axial, free-sporing diplohaplontic embryophytic land plant of the Early Devonian that had anatomical features more advanced than those of the bryophytes.
In 1859 he published a reconstruction of a Devonian plant, collected as a fossil from the Gaspé region of Canada, which he named Psilophyton princeps. The reconstruction shows horizontal and upright stem-like structures; no leaves or roots are present.