Thelidium A.Massal.
Thallus crustose, ecorticate, poorly developed. Photobiont green, Protococcus. Ascocarps in the form of perithecia, simple or compound, immersed or superficial, horny, carbonaceous. Paraphyses becoming gelatinised. Ascospores colourless to brown, ellipsoid to oblong-ovoid, 1- to 3-septate, sometimes with 1-2 spurious longitudinal septa often with a large oil droplet, 8 per ascus.
Key
Thelidium, included in the family Verrucariaceae is a cosmopolitan genus of c. 100 species. The genus is poorly understood and very much undercollected in New Zealand, and is much in need of study here. Three species are recorded, two from limestone.
