Pecopteris (Asterotheca) saraeiP. Corsin, 1951, forme fertile de Sphenopteris damesii (Stur, 1885)

Sphenopteris damesii (Stur), a rather frequentspecies from the Sarre-Lorraine Coalfield was only known till now as a typical sphenopteridian sterile foliage. The study of a lot of specimens from recent boreholes has allowed us to show the great polymorphism of this species whose foliage, usually deeply dissected, tends to be pecopteridian in the fertile stage.The organization of fructifications and the type of included spores are described for the first time. Moreover, the comparison of the fertile specimens of Sph. damesii with those from the same horizon described by P. Corsin as Pecopteris saraei has revealed similarity in limb morphology, in the organization of fructifications, in the type of spores which proves that P. saraei is the fertile form of Sp. damesii. Consequently, P. Corsin's species is a posterior synonym of Sphenopteris damesii (Stur).The generic attribution of this species sets a nomenclatural question: the features of the fructifications agree exactly with the diagnose of the genus AsterothecaPresl but this genus till now was reserved for sporangia born by typical pecopteridian foliage. Nevertheless, the species is temporarily refered to Asterotheca until further works allow to decide about the subordination of these different characters.