Diagnostic features
Small spherical to ovoid unicells, surrounded by a thin sheath of remnant wall material. Single parietal chloroplast containing a large pyrenoid with visible starch grains surrounding it (identical to the pyrenoid of Klebsormidium, to which it is closely related). Division without sporangia (simple division into two daughter cells).
![[Interfilum], X1000. Photo: Phil Novis, Manaaki Whenua Image](/assets/Tools-And-Resources/Identification/algae/interfilum_phil1000__ScaleWidthWzEwMjRd.jpg)