Abstract
The morphology and ultrastructure of the spores of the enigmatic Lower Devonian plant Parka decipiens are briefly described and previous interpretations of the plant are discussed. It is suggested that the alete spores of Parka could have been haploid or diploid. The possibility that some early plant spores were diploid may be viewed as supporting the interpolation theory for the origin of alternation of generations in land plants. The spores of Parka may lie (in morphological and developmental terms) somewhere between the oospores produced by algae and the triradiate haploid spores of the bryophytes.