Sagenidium Stirt.
Type : Sagenidium molle Stirt.
Description : Flora (1985: 518).
Sagenidium is a genus of two species (Follmann 1975; Henssen et al. 1979; Kirk et al. 2001), included in the family Roccellaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005) occurring in the Southern Hemisphere in New Zealand, Tasmania and Chile. Sagenidium is characterised by a byssoid habit where the thallus is composed of loosely interwoven threads and appears rather cottony; Trentepohlia as photobiont; lecideine, plane, black apothecia with densely white-pruinose discs; and fusiform, transversely septate ascospores. For a comparison of byssoid lichens (Coenogonium, Conotremopsis, Cystocoleus, Dictyonema, Jarmania, Roccellinastrum and Sagenidium) see Kantvilas (1996d). Two species were earlier recorded from New Zealand (Follmann 1975; Galloway 1985a: 518–519), but this is now regarded as unjustified and only one species appears to be present here.
