Several species recorded in the Netherlands island of Schiermonnikoog are discussed. Cochlearia anglica L. found in the southern part of the island proved to be octoploid (2n = 48). The Netherlands material of 1 C. officinale L. ishexaploid (2n = 36) and cytologically and morphologically intermediate between the British C. officinale (tetraploid, 2n = 24) and C. anglica. The Ornithogalum umbellatum complex is represented by two taxa. Both the triploid O. umbellatum L. s.str. and the penta-/hexaploid O. divergens Bor. can be found near the village of Schiermqnnikoog; probably the plants are not indigenous there. Of Ranunculus ficaria L. only the subsp. bulbifer Lawalree was found. Stellaria graminea L. is mostly diploid (2n = 26) in the Netherlands and elsewhere in Europe. All plants from Schiermonnikoog, that were counted, proved to be tetraploid (2n = 52). No morphological differences between the two cytotypes could be found. Of Symphytum officinale L. only one population was discovered. The plants are tetraploid (2n = 48) and purple or white flowered. Veronica hederifolia L. occurs on the island in two forms, viz. the tetraploid V. sublobata Fiseh (2n = 36) and the hexaploid V. hedehfolia L. s.str. (211 = 54).