First Report of the Early Spore Stages of Sunflower Rust, Caused by <i>Puccinia helianthi</i>, in Nebraska

Fig. 4. Young aecia (yellowish structures) forming on bottom of leaf additionally infected with uredial pustules (brown lesions).



Image from Plant Health Progress article:
First Report of the Early Spore Stages of Sunflower Rust, Caused by Puccinia helianthi, in Nebraska