Pteridologische aantekeningen, 2, Dryopteris tavelii in Nederland

Dryopteris tavelii Rothm. (fig. 1, c—h) has been found in the Netherlands in several localities. The morphological characters are enumerated and compared with those of D. filix-mas (L.) Schott (fig. 1, a—b) and D. borreri Newm. (fig. 1, i). D. tavelii showing a considerable variation in its characters, the rather current opinion that all its forms resemble habitually D. borreri much more than D. filix-mas, is erroneous. The possible occurrence of secondary hybridization (D. tavelii ♂ X D. filix-mas ♀) must not be excluded. Not all forms of the hybrid-swarm reproduce apogamously, a quite sterile form, with relatively many characters of D. filix-mas, having been found at Winterswijk. D. borreri has never been recorded from the Netherlands. Correctie bij Pteridologische aantekeningen, 1: In Gorteria 1 (6), p. 58, 3e alinea, regel 8—10, leze men: Sporen van A. ruta-muraria zijn ongeveer 50—51 µ lang, van A. adiantum-nigrum (s.s.) ongeveer 44 µ en van de bastaard meestal kleiner dan 27 µ.