First Report of Powdery Mildew of Poison-Hemlock Caused by <i>Erysiphe heraclei</i> in North America

Fig. 2. Lobed appressorium of Erysiphe heraclei from Conium maculatum leaf. Scale bar = 15 ┬Ám.



Image from Plant Health Progress article:
First Report of Powdery Mildew of Poison-Hemlock Caused by Erysiphe heraclei in North America