Comparative Morphology of Fatsia japonica, Hedera helix, and Their Hybrid, × Fatshedera lizei

Abstract

Abstract Micromorphology and chromosome number of Fatsia japonica Decne et Planch. ‘Moseri’, Hedera helix var. hibernica Kirchn., and their putative intergeneric hybrid, × Fatshedera lizei are surveyed. × Fatshedera lizei is intermediate in most characteristics of leaf surface morphology. Both H. helix and F. japonica have 2n = 48 chromosomes; a range of counts from 72-98 for × F. lizei suggests that it may be an unstable tetraploid. Comparisons of chromosome size suggest that both parental genomes are represented in the the karyotype of × F. lizei. Certain novel characteristics of the hybrid (inflorescence morphology, petiole morphology and anatomy, leaf vascular anatomy) are possibly the result of phenotypic expression of the hybrid genome or polyploid effects. Micromorphological characteristics can provide evidence of hybrid intermediacy when gross morphological features do not clearly identify hybrid origin.