Spore Surface Morphology of Hawaiian Acacia Rust Fungi

ABSTRACT

Certain spore states of rust fungi on endemic Acacia spp. in Hawaii are typified by pedicellate spores with reticulate wall ornamentation and a series of equatorial germ pores. These spore states include aeciospores and urediniospores of the macrocyclic form of Uromyces digitatus, aeciospores of U. koae, and teliospores of Endoraecium acaciae and E. hawaiiense. Reticulate spores of this type are apparently rare among the rusts. Spore ornamentation of the Hawaiian rusts is similar to that found on other Acacia rusts in Australia, New Zealand, Taiwan, and Japan. The similarity of morphology and host may indicate a close phylogenetic relationship among these forms.

Key Words:

• Acacia spp.
• Uredinales
• spore morphology