Of Cerastium holosteoides Fr. three subspecies occur in the Netherlands. Subsp. triviale (Murb.) Möschl is common throughout the country, subsp. holosteoides and subsp. pseudoholosteoides Möschl are very rare and only found in a few localities in the tidal area of our larger rivers (island of Dordrecht; Biesbosch). The three subspecies may be distinguished as follows: 1. Leaves hairy above. Indumentum of the plant consisting of long, very acute hairs, whether or not mixed with glandular ones.............. subsp. triviale 1’. Leaves glabrous above, at most ciliate at the margin. 2. Indumentum of the plant consisting of very acute hairs, which are, however, shorter than in subsp. triviale; glandular hairs present or lacking (fig. 1, b-c) subsp. holosteoides 2’. Indumentum of the plant exclusively consisting of short, obtuse hairs; glandular hairs always lacking (fig. 1, a).......... subsp. pseudoholosteoides