ON THE MORPHOLOGICAL VARIATION IN ORTHOTRICHUM HOOKERI MITT.

Abstract

  The endostomes in Orthotrichum hookeri Mitt. are shown to vary from individuals with 16 lanceolate-triangular segments to plants with 8 linear-lanceolate segments with all possible intermediate forms being present. Together with the variation observed in leaf shape and exsertedness of capsules this indicates a less advanced evolution than that exhibited in related species in e.g. South America.