Life cycle separates Puccinia pachycephala from P. metanarthecii

• Puccinia metanarthecii and P. pachycephala differ in life cycle and morphology.
• Puccinia metanarthecii host-alternates between Ixeris and Metanarthecium or Aletris.
• Puccinia pachycephala host-alternates between Ligularia and Veratrum.
• Aeciospores and teliospores are larger in P. pachycephala than in P. metanarthecii.

Puccinia metanarthecii and P. pachycephala differed in their heteroecious life cycle. The former rust fungus formed spermogonial/aecial stages on Ixeris dentata and uredinial/telial stages on Metanarthecium luteo-viride or Aletris foliata. The latter formed spermogonial/aecial stages on Ligularia hodgsonii and uredinial/telial stages on Veratrum maackii var. longibracteatum and V. maackii var. parviflorum. Puccinia pachycephala and P. metanarthecii can also be differentiated by aeciospore and teliospore morphology.