Ornithogalum umbellatum L. en O. divergens Bor. in Nederland

In the Netherlands two groups of plants can be distinguished in Ornithogalum umbellatum L. s.l., which differ morphologically and cytologically. The first group consists of triploids and some tetraploids, the second of penta- and hexaploids and also some tetraploids. The characters of the triploids (2n = 27) are: bulbs higher than broad; bulbils few and oblong; more than 15 leaves (up to 5 mm broad) per bulb; inflorescences few-flowered (5—12 flowers); pedicels not deflected after anthesis. The characters of the penta- and hexaploids (2n = 45, 54 respectively) are: bulbs broader than high; bulbils many, small and round; leaves up to 12 (5—8 mm broad); inflorescences many-flowered (usually more than 14 per inflorescence); pedicels always deflected after anthesis. The seed-set is extremely low in all cytotypes. Taxonomically the most plausible solution seems to assign the triploids to O. umbellatum L., the penta- and hexaploids to O. divergens Bor. The latter taxon was probably introduced from S. or C. Europe and often occurs in the Netherlands near estates and country seats. Perhaps they can be considered as „stinseplants”.