Dormancy and salt-tolerance in two spontaneous species of Hordeum. — Dormancy behaviour and germination capacity in salt-solutions ofHordeum murinumL. andHordeum marinumHuds. seeds have been studied. Seeds (caryopses) have been sown in Petri dishes on filter paper soaked with deionized water (control) or with NaCl solutions at concentrations: 3.2 - 6.5 - 13.0 - 26.0%. Germination was tested during after-ripening, 20, 40, 60, 100, 160, 260 and 365 days from harvest (fully ripe seeds). The two species ofHordeumare spontaneous and characterized by peculiar ecological features. The present results have shown that, during the first year from harvest,Hordeum murinumandH. marinumhave different length and strength of dormancy (longer and stronger inH. marinumthan inH. murinum). Germination capacity and energy of the two species — during after-ripening stage — when seeds are sown in salt-solutions differ strongly and seem to be correlated with dormancy.Hordeum murinumseeds, which exhibit a dormancy shorter than those ofH. marinum, germinate earlier when sown on salt-solutions. Besides, germination energy ofH. murinumseeds is, in all assayed solutions, during 260 days from ripening, significantly higher than the one ofH. marinum. This species, sown in NaCl solution at concentration 26%, shows a reduced germination capacity. Germination behaviour of the twoHordeumspecies does not seem to agree with their ecological features as shown byH. marinum. This is present in halophilic associations of coast shores and shows a higher salt-tolerance thanH. murinum.