The species of Thecaphora on Compositae in North America
Keyword(s):
New Host
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Five new species of Thecaphora collected in Mexico are described, some of which are parasitic on genera of Compositae not previously reported as hosts. Species of Thecaphora on Compositae for the North American continent now total 11. New species include Thecaphora denticulata, T. heliopsidis, T. hennenea, T. melampodii, and T. neo-mexicana. New host genera for North America include Bidens, Heliopsis, and Melampodium. Morphological characteristics of Thecaphora species and taxonomic criteria to delimit them are discussed. Keys to the species, interpretations of spore ball morphology and spore sculpturing, and scanning electron and bright-field micrographs are presented.