Stigmaria BRONGNIART

Cleal, Christopher J. & Thomas, Barry A., 2018, Nomenclatural Status Of The Palaeobotanical “ Artificial Taxa ” Established In Brongniart’S 1822 “ Classification ” Paper, Fossil Imprint 74 (1 - 2), pp. 9-28 : 15

Stigmaria BRONGNIART

1820 Variolaria STERNBERG , p. 22 (nom. illegit., non Variolaria PERSOON, 1795 ).

1822a Stigmaria BRONGNIART , p. 209.

Ty p e. Variolaria ficoides STERNBERG, 1820, p. 24 , pl. 12, fig. 1–3 (vide Kvaček and Straková 1997); preserved syntype NM-E 80; Loc.: Radnice Member (upper Bashkirian Stage), Radnice, the Czech Republic; photographically refigured by Kvaček and Straková (1997: pl. 18, fig. 5); ≡ Stigmaria ficoides (STERNBERG) BRONGNIART, 1822a .

D i a g n o s i s. “Tiges sans articulations ni cannelures, impressions arrondies, espacées, disposées en quinconce.”

D i s c u s s i o n. Brongniart rejected Sternberg’s earlier published name of Variolaria for this fossil-genus because it was pre-occupied by the name of a lichen genus, Variolaria PERSOON, 1795 . As Brongniart clearly regarded Stigmaria as a replacement name for Variolaria STERNBERG and not a new genus, the type of the former must be taken as the type of the latter, not the specimen figured by Brongniart (1822a: pl. 1, fig. 7).

Stigmaria is now used for the rhizomorphs of various arborescent lycopsids with upright stems assignable to fossilgenera such as Lepidodendron STERNBERG , Lepidophloios STERNBERG, 1825 and Sigillaria BRONGNIART. The Stigmaria rhizomorphs that were attached to these different types of upright stems are indistinguishable morphologically and anatomically, and so it is impossible to assign them to a particular type of stem. Stigmaria should, therefore, be retained for these fossil rhizomorphs in all modes of preservation (see Thomas and Seyfullah 2015).