W. extenuata is an exceedingly common weft-forming moss of wet forest and rainforest. It has an untidy appearance and typically grows on logs or terrestrially and is also often found creeping up the bases of trees. The shoots, particularly the main one, distinctively end in spiky points, thereby giving rise to the colloquial appellations for the species like 'Spiky Wiki' or Spear moss. 

It is superficially similar to Calliergonella cuspidata but differs in being a bit for wiry looking and having an easily discernable long hairpoint on the leaves.