A chromatographic and cytological study of Dryopteris dilatata in North America and eastern Asia

Abstract

A chromatographic analysis of the phloroglucinol derivatives of 123 collections of Dryopteris intermedia Gray (2x), D. assimilis S. Walker (2x) from western North America, D. "dilatata" from eastern North America (2x), D. "austriaca" from Japan and Kamchatka, "Aspidium dilatatum" from Siberia, D. campyloptera Clarkson (4x) from eastern North America, D. spinulosa Watt (4x) from North America, the hybrids D. "dilatata" × campyloptera (3x) and D. intermedia × spinulosa (3x) is presented. D. "dilatata" from eastern North America has an extremely variable phloroglucinol content, which limits the utility of the analysis for taxonomy. The chromatographic and cytological results are discussed in connection with the evolution of the two tetraploid taxa, D. campyloptera and D. spinulosa. The intra-specific variability of each taxon is discussed and compared with the extensive European studies. The material investigated may be considered to belong to the following species: D. intermedia Gray (2x), D. assimilis S. Walker (2x), D. campyloptera Clarkson (4x), and D. spinulosa Watt (4x). Only two different ancestral genomes are considered to be present in these four species, one in the first three species, and two in D. spinulosa.