The gametophyte of some species found within this subclass can either be thalloid while some are occasionally foliose. Those that are thalloid will lack internal tissue differentiation, thereby classifying them as “simple thalloid liverworts”.
A closer look at the middle of the thallus will reveal the presence of a central strand of dead water conducting cells within it.
Another characteristic shared among the species within this subclass are the multicellular spores.