Venturia species on poplars of the section Leuce II. Cultural study. Monospore strains of V. macularis (Fr.: Fr.) Müller and v. Arx, V. viennotii Morelet, V. tremulae Aderh., var. tremulae, var. populi‐albae Morelet, and var. grandidentatae Morelet, are compared in vitro for their growth and fruit‐body induction (anamorph and teleomorph) under different conditions.