The Collaborative International Dictionary of English v.0.48:
Apothecium \Apo`*the"ci*um\, n.; pl. Apothecia. [NL.] (Bot.) The ascigerous fructification of lichens, forming masses of various shapes. [1913 Webster] ApothegmWordNet (r) 3.0 (2006):
apothecium n 1: a cuplike ascocarp in many lichens and ascomycetous fungi