Pilularia minuta is a small and delicate fern. The creeping
stem measures approximately long and in diameter. Each mature stem consists of twelve or more segments, with individual internodes measuring long. The nodes each bear a single leaf, one or two roots, and sometimes a new bud or branch. The roots are usually simple but may be branched. The upright, slender leaves measure long and in diameter. When fruiting, the
sporocarp, bearing a spherical capsule, arises from a stem node at the base of the leaf and is covered in tawny hairs. Mature sporocarps are borne on
peduncles. ==Ecology==