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An experimental crossing program was carried out in order to test the hypothesis thatArmeria villosa subsp.carratracensis, a serpentine endemic from Southern Spain, is of hybrid origin. Fruit-set and mainly pollen stainability data in artificial hybrids demonstrate that internal interspecific barriers are weak. Two generations of backcrossing with the two putative parents —A. colorata andA. villosa subsp.longiaristata— can restore pollen stainability to an average of 83.2 and 68.7, respectively. A morphometric analysis of 148 specimens belonging to parental species, different artificial hybrid generations and wild putative hybrid race shows that (1) morphological characters have a strong genetic basis and thus are good markers in identifying hybrids and introgression inArmeria; (2) artificial backcrossing produces in morphometrical characters a variation which conforms in both trend and magnitude to what is commonly attributed in the wild to introgression; (3) the position of the putative hybrid race is intermediate between the two parental species used in the program. These results are in accordance with the hypothesis of hybrid origin ofA. villosa subsp.carratracensis.