The stipe is sparsely covered in narrow basal scales, which are pale to dark and have broad fragile edges.

Characteristically of this species, the lowest one or two pairs of pinnae may be slightly reduced and occur towards the base of the stipe.

Sori are located near the pinnule midvein and are partially or fully covered by indusia, which open towards the pinnule margin.

[2] Large and Braggins (2004) note that there is much variation between individual plants of C. affinis in terms of frond and scale details and Cyathea tahitensis, which is usually regarded as synonymous, may in fact represent a separate species.

[1] Young shoots of C. affinis are eaten in the Marquesas Islands.