Part 186. The spore-base lichens (Class Basidiolichenes) include only a few tropical forms of symbiotic Basidiomycetes which may be represented by the mushroom-lichen (Cora pavonia, Fig. 337). This consists of one of the tougher mushrooms associated with a Chroöcoccus, or with another bluish alga, and assumes quite different shapes according to which alga is present and according as the algal or the fungal symbiont predominates and so determines the form.

Fig. 337. Mushroom lichen (Cora pavona, Mushroom lichen Family, Coraceoe). A, top view of fruit body, natural size. B, under side showing hymenium (hym). (Strasburger.) On trees in the tropics.

Fig. 337.-Mushroom-lichen (Cora pavona, Mushroom-lichen Family, Coraceoe). A, top view of fruit-body, natural size. B, under side showing hymenium (hym). (Strasburger.)-On trees in the tropics.