On flowers, watersoaked to brown flecks which may enlarge rapidly to become large tan to brown areas, appear on the petals. This can quickly spread to nearby petals as well. The fungus may grow down the flower stalk , causing it to collapse. Buds may rot. The fungus may also infect stems, causing a tan to brown canker to develop on the stem, or they may die back from pruning wounds.
Cankers can weaken the stem.
They may cause the plant to wilt, perhaps die, and to fall over. On some plants, the crown can become rotted. Cuttings can rot from the base. On all infected plant parts, in high humidity the fungus will produce characteristic spores . All affected areas become covered with a fuzzy gray fungal growth.