a. Bot. [f. EPI- + BASAL a.] The distinctive epithet of the upper of the two cells in the oösphere of certain cryptogams. (See quot.)
1882. Vines, Sachs’ Bot., 375. The oospore is first of all clothed with a cell-wall, continues to grow considerably, and is then divided by a horizontal or slightly oblique wall (basal wall). The lower (hypobasal) of these two cells … contributes but little to the formation of the embryo. The upper (epibasal) cell gives rise to the capsule and the seta.
