CYTOTAXONOMY OF THE SPECIES AND INTERSPECIFIC HYBRIDS OF THE GENUS ELYMUS IN CANADA AND NEIGHBORING AREAS

摘要

A cytotaxonomic treatment is given for 12 native species, 2 introduced species, and 3 natural interspecific hybrids of the genusElymusL. that occur in Canada. Five of the nativeElymusspecies and an additional natural interspecific hybrid are found in Alaska. Eleven of the native species, one introduced species, and two of the natural interspecific hybrids are present in the mainland United States. Some additional native species and natural interspecific hybrids ofElymusfrom the mainland United States are treated briefly.Nomenclatural proposals include:ElymusglaucusBuckl. var.virescens(Piper) Bowden;E. times;uclueletensisBowden (E. mollisTrin. f.mollis times; E.glaucusBuckl. var.glaucus);E. times; aleuticusHulteacute;n (pro sp.) (E.mollisTrin. f.mollis times; E.hirsutusPresl);E. canadensisL. var.wiegandii(Fern.) Bowden f.wiegandiiand f.calvescens(Fern.) Bowden;E. times;malteiBowden nm.maltei, nm.simulansBowden, nm.churchiiBowden, and nm.browniiBowden (E. virginicusL. times;E. canadensisL.);E. virginicusL. var.jenkinsiiBowden;E. hystrixL. var.bigelovianus(Fern.) Bowden;E.piperiBowden;E. innovatusBeal subsp.innovatusvar.glabratusBowden; andE. triticoidesBuckl. var.pacificus(Gould) Bowden.HystrixpatulaMoench is here treated asElymushystrixL.Voucher specimens are cited for the following chromosome number determinations:(1) diploid, 2nensp;=ensp;14:Elymusjunceus.(2) tetraploid, 2nensp;=ensp;28:Elymus canadensisvar.canadensis, E. canadensisvar.wiegandiif.wiegandii, E. diversiglumis, E. glaucusvar.glaucus, E. glaucusvar.virescens, E. hirsutus, E, hystrixvar.hystrix, E. hystrixvar.bigelovianus, E. innovatussubsp.innovatusvar.innovatus, E. times; malteinm.maltei, E. riparius, E. sibiricus, E. villosusf.villosus, E. virginicusvar.virginicusf.virginicus, andE. virginicusvar.submuticus.Earlier literature reports (based on voucher specimens) are given for the following:(1) tetraploid, 2nensp;=ensp;28:Elymus mollis(two subsp. and three forms),E. piperi, andE. times; vancouverensisnm.crescentianus.(2) hexaploid, 2nensp;=ensp;42:Elymus times; vancouverensisnm.vancouverensis, andE. times; vancouverensisnm.californicus.(3) octoploid, 2nensp;=ensp;56:Elymus arenarius, E. innovatussubsp.velutinus, andE. piperi.