a. Bot. [f. TAPET(UM + -AL.] Of or pertaining to the TAPETUM (2).
1868. R. Owen, Anat. Vertebrates, III. 252. The tapetal layer exists in most [Carnivora], and consists of obscurely nucleated cells.
1882. Vines, Sachs’ Bot., 480. These divisions produce a tapetal layer at an early stage which surrounds each group of spore-mother-cells. Ibid. (1882), in Nature, 19 Oct., 595/2. The surrounding protoplasm which is derived from the disorganised tapetal cells.
