PHLOROGLUCINOL DERIVATIVES IN DRYOPTERIS FILIX-MAS (L.) SCHOTT AND ITS PUTATIVE ANCESTORS (PTERIDOPHYTA, DRYOPTERIDACEAE)

摘要

North American Dryopteris filix-mas (L.) Schott consists of two distinct geographical types, a western taxon, which corresponds with the European plant, and an eastern taxon, which differs slightly in its mophology, phloroglucide-chemistry and cytology. The cytology strongly suggests that the latter cannot be a distinct amphidiploid involving D. marginalis (L.) A. Gray as a diploid ancestor, but most likely had a similar genomic origin to the European plant. The chemistry and morphology, however, appear to suggest some participation of D. marginalis within it. This is postulated to have occurred through the medium of the frequent hybrids between it and D. marginalis, but the actual mechanism remains unknown. The eastern N. American plant is described from Canada as a new subspecies, D. filix-mas subsp. brittonii Fras.-Jenk. & Widen. The hybrid between this taxon and D. marginalis is described as D. x montgomeryi Fras.-Jenk. & Widen.