Two new species of Leptogium (Collemataceae) with transversely septate ascospores from East Africa

Two epiphytic Leptogium species from East Africa, both with transversely septate ascospores, are here described as new. They produce plicate thalli and have a paraplectenchymatous proper exciple and a one cell layer thick cortex on the thalline exciple. Leptogium bellum has so far only been collected from Mt. Kilimanjaro, Tanzania, where it occurs from mid- montane forests up to the subalpine zone. Leptogium tiinae occurs in relatively open habitats at lower elevations, with the type specimen collected from the Taita Hills, Kenya. Additionally, details from a Leptogium chloromeloides isotype and a key for Leptogium species with transversely septate ascospores are provided.