Chlamydomyxa labyrinthuloides is a heterokont alga known since the last century. It lives on Sphagnum and other water plants as
aplanospores or plasmodia. We have investigated the taxonomic position of Chlamydomyxa labyrinthuloides by combining results from
morphological studies, pigment analyses and a molecular phylogenetic analysis of the small subunit (SSU) rRNA gene. Chlamydomyxa
labyrinthuloides shares morphological features with xanthophytes and chrysophytes, whereas pigment composition indicates a grouping
with the phaeophytes, raphidophytes and chrysophytes. The sequence of the SSU rRNA gene and its phylogenetic reconstruction
unambiguously demonstrate that Chlamydomyxa labyrinthuloides is related to the chrysophytes.
