How to recognize Fissidens subbasilaris: This moss has small plants, with oblong leaves in as many as 28 pairs, with broadly acute to rounded obtuse leaf tips and margins evenly crenulate all around. The single costa ends 6-20 cells below the tip. Under the microscope the significant difference of this species can be seen: the costa is not distinct but covered with little cells similar to those of the leaf; these extra cells obscure the midrib that is seen clearly under the microscope in other species of Fissidens. The cells of the leaf are bulging, and in places other than the costa are doubly layered.
Where to find Fissidens subbasilaris: Look for this moss on tree trunks or bare calcareous rocks and boulders.