New species of Clavulina from Guyana.

Two new species of Clavulina are described from rainforests dominated by ectomycorrhizal Dicymbe spp. (Caesalpiniaceae) in the Pakaraima Mountains of Guyana. Clavulina nigricans, sp. nov. is unique for Clavulina in having 4-6 spores per basidium. Clavulina craterelloides, sp. nov. has an infundibuliform basidiome, previously unknown in the otherwise coralloid genus Clavulina. Macromorphological, micromorphological and habitat data are provided for each taxon, as well as justification for their placement in Clavulina based on morphological and molecular features.