Diplasiolejeunea involuta Winkler, a species formerly known only from El Salvador, was collected from shrubs in a non pure Sphagnum - Blechnum bog in Costa Rica. The plant is easily recognized by its large leaves, very convex lobes and very large lobules with obviously involute apex; the species has 3-7 oil bodies of the Jungermannia type per cell. Most characteristics of D. involuta fit with those of the subgenus Austrolejeuneopsis, the size of the underleaves are like those of the subgenus Diplasiolejeunea and the stout lobule covers up to 85% of the lobe, as in the subgenus Physolejeunea
