Studies of Cionothrix (Uredinales): emendation, telial morphology and description of a new species
The genus Cionothrix of rust fungi (Uredinales: Pucciniaceae, tribe Pucciniosireae) has tendril-like telial threads composed of one-celled teliospores. It has been distinguished from similar genera in Pucciniosireae mainly by the absence of intercalary cells between the teliospores. Reexamination of C. praelonga, the type species of Cionothrix, and two other Cionothrix spp. revealed that intercalary cells occur in all three of them. An emended description of Cionothrix is provided and its delimitation from similar genera is discussed. Cionothrix nudicolla from Costa Rica is proposed as a new species. It differs from the known species in the absence of ostiolar paraphyses and large teliospores with uniformly thin spore wall.