Coccomyces hiemalis - Коккомицес зимний - Winter Coccomyces

Coccomyces hiemalis - Коккомицес зимний - Winter Coccomyces - Winterlicher Fleckenpilz 8/23/15

Coccomyces hiemalis is a noteworthy species of fungi belonging to the family Rhytismataceae within the Ascomycota phylum. This fungus is known to occur in North America and Europe, particularly in temperate regions with moist environments. Coccomyces hiemalis primarily infects the leaves of deciduous trees and shrubs, such as Prunus and Rosa species, causing a leaf spot disease. The fruiting bodies of Coccomyces hiemalis, called apothecia, appear as small, circular to irregular, black or dark brown spots on the surface of infected leaves. These spots typically measure 1 to 3 mm in diameter and may coalesce, forming larger patches on the leaf surface. The fungus overwinters on fallen leaves and releases spores during the following spring, which then infect new leaves. The asci of Coccomyces hiemalis typically contain eight spores each, a characteristic feature of fungi in the Ascomycota phylum. The spores are elliptical in shape, measuring approximately 10-15 x 4-6 µm, and are hyaline, which makes them almost transparent. Each spore typically has one septum, or crosswall, that divides it into separate cells. Coccomyces hiemalis is considered a plant pathogen, causing leaf spot disease in various deciduous trees and shrubs. While the disease can lead to unsightly leaf spots, premature leaf drop, and reduced photosynthesis, it rarely causes significant harm to the overall health of the plant. In some cases, however, severe infections may result in reduced growth or defoliation. As Coccomyces hiemalis is a plant pathogen and not a mushroom-forming fungus, it is not edible. Its primary importance lies in its impact on the health of deciduous trees and shrubs and as a subject of study for plant pathologists, mycologists, and naturalists. To manage leaf spot disease caused by Coccomyces hiemalis, it is recommended to collect and dispose of infected leaves during the fall season, which helps to reduce the source of inoculum and limit the spread of the fungus to new leaves in the following year. Fungicides are generally not recommended, as leaf spot disease is usually not severe enough to warrant their use.