Cell of X. fasciculatum. The cell wall in the centre of the semicell is furnished with a circle of granules. Notice that all spines at the angles are paired (in contrast to X. cristatum). Notice also the big, additional granule at each of the basal angles (characteristic of var. oronense).
Cell dimensions (L x B): 66 x 64 µm
X. fasciculatum much resembles X. cristatum. In general, cell length to breadth ratio in X. fasciculatum is somewhat lower than in X. cristatum. Most decisive differentiating character, however, is found in the number of spines near each of the basal angles: a single one in X. cristatum versus a pair in X. fasciculatum. In the Netherlands X. fasciculatum is of rare occurrence in slightly acidic, mesotrophic habitats, in particular quaking fen hollows.