19 plants of Ornithogatum umbellatum, originating from 7 different populations, were cytologically investigated. All plants proved to be triploid (2n = 27). In spite of sexual reproduction no aneuploid individuals could be found up till now. The author agrees with the Polish botanist Dr. R. Czapik that it is likely that the unbalanced aneuploids are not able to survive. The increase of the number of individuals is probably largely (or entirely) the result of vegetative reproduction.