Bot. [mod.L., a. Gr. θηκίον, dim. of θήκη THECA.] The HYMENIUM of a lichen.
1882. J. M. Crombie, in Encycl. Brit., XIV. 554/1. The two principal parts of which an apothecium consists are the hypothecium and the thecium. Ibid., 554/2. The thecium, or as it is more frequently termed the hymenium, is that part of the apothecium which contains the organs of the fruit.
