Nothia was a genus of Early Devonian vascular plants whose fossils were found in the Rhynie chert in Scotland.

[1] Fossilized remains, including bare stems (axes) and detached spore-forming organs (sporangia), were first described by Kidston and Lang in 1920 from the Rhynie chert of Aberdeenshire, Scotland – rocks which are of Pragian age (413 to 411 million years ago).

In 1964 Lyon described sporangia belonging to Asteroxylon mackiei and suggested that Kidston and Lang's specimens were a new species which he called Nothia aphylla.

[4] Both the horizontal rhizomes and the vertical stems had vascular tissue which formed a central core (protostele), and is described as having centrarch development.

[1] Kerp et al. suggest that Nothia aphylla was a geophyte which inhabited sandy soils and had a clonal life-style.

[1] Nothia has been placed in the group initially established by Banks as the subdivision Zosterophyllophytina or the class Zosterophyllopsida (zosterophylls).

A cladogram published in 2004 by Crane et al. places Nothia in a paraphyletic stem group of broadly defined "zosterophylls", basal to the lycopsids (living and extinct clubmosses and relatives).

[7] † Hicklingia Adoketophyton, Discalis, Distichophytum (=Rebuchia), Gumuia, Huia, Zosterophyllum myretonianum, Z. llanoveranum, Z. fertile Zosterophyllum divaricatum, Tarella, Oricilla, Gosslingia, Hsua, Thrinkophyton, Protobarinophyton, Barinophyton obscurum, B. citrulliforme, Sawdonia, Deheubarthia, Konioria, Anisophyton, Serrulacaulis, Crenaticaulis Nothia, Zosterophyllum deciduum extant and extinct members A detailed study of Nothia aphylla questions this positioning of the genus, concluding that its taxonomic placement remains unclear, and that the cladistic analyses of Kenrick and Crane (on which the above cladogram is based) have ignored "fundamental differences" between different kinds of emergences (protrusions from stems).

Features of the vascular tissue of typical zosterophylls, such as characteristic thickenings of the cells which conduct water, are also absent in Nothia.