New Species, New Combination and An Identification Key of the Genus Elymus (Poaceae: Triticeae) in Iran

The genus elymus has been studied to prepare the draft of elymus for the flora of iran. in this research, the plant specimens of central herbarium of iran (tari) were identified and a new key of the iranian species of the genus elymus is presented. delimitation of the genus is discussed. among the specimens, a new species from zagros mountain ranges was recognized which is described and illustrated as e. shirazicus. the new species is well characterized among the iranian species of the genus by caespitose habit, having densely imbricate spikelets with none or short awns. elymus shirazicus seems to be related to e. transhyrcanus but well distinguished by narrower spikes and much shorter rachis internodes. elymus dorudicus based on e. nodosus subsp. dorudicus is introduced as a new combination. elymus lazicus subsp. iranicus is described as a new subspecies.