Sawdonia is an extinct genus of early vascular plants, known from the Upper Silurian to the Lower Carboniferous (430 to 320 million years ago).

In 1971 Francis Hueber proposed a new genus for this species due to its "Divergent technical characters from the generic description for Psilophyton.

Sir J. William Dawson Collection, Peter Redpath Museum, McGill University, Montreal, Quebec, Canada.

[1] These plants are described by Hueber as having monopodially branched stems, that are unridged, spinous and circinately tipped.

In their 1997 cladistic study, Kenrick and Crane placed Sawdonia in the family Sawdoniaceae, order Sawdoniales.