postical
/ˈpɒstɪkl/ /pɒˈstʌɪkl/adjective
Botany. Of, relating to or designating the lower (ventral) surface of a liverwort stem.
Origin
Mid 17th century (in an earlier sense). From classical Latin postīcus situated at the back, rear + -al. With sense 1 compare earlier postic.