Cystomyces antheropori , a new rust fungus on Antheroporum glaucum from Thailand

A rust fungus was found on leaves of Antheroporum glaucum (Fabaceae, Faboideae) in Provinces of Petchaburi and Ratchaburi, western Thailand. No rust fungus was previously reported on this legume tree species. The new rust fungus was apparently microcyclic, producing telia surrounding dense aggregates of spermogonia, on the abaxial leaf surface. Teliospores were produced by sympodial proliferation from a basal sporogenous cell and mostly composed of three fertile cells subtended by two hygroscopic cysts. A germ slit was present near the septum in two of three fertile cells. A simple persistent pedicel was attached to the teliospore cysts. Because of resemblance in the teliospore morphology, this fungus was compared to Bibulocystis, Caetea, Cystomyces, and Spumula. Radially symmetric teliospores in the horizontal plane with three more or less globose fertile cells subtended by two hygroscopic cysts and the presence of a germ slit near the septum in fertile cells are the characteristics of the genus Cystomyces. Therefore, it was concluded that the fungus should be classified in Cystomyces, and a new name, C. antheropori was proposed.