Black cup fungus

The black cup fungus (Plectania melastoma) is an ascomycete fungus belonging to the Sarcoscyphaceae family. In agronomy and forest pathology, this organism is recognized as a pathogen or decomposer that affects the tissues of woody plants, particularly those that are already stressed or decaying.

The pathogen is a member of the Ascomycota phylum. The disease type involves the colonization of woody host tissues through wounds or bark cracks. While often acting as a saprotroph, it can exhibit opportunistic parasitic behavior on weakened trees, accelerating the breakdown of cellulose and lignin within the wood structure.

The affected cultures primarily include various broad-leaved trees and occasionally coniferous species. The fungus is commonly found in forest soils, shaded nursery areas, and damp garden patches, thriving where there is significant organic debris and high environmental humidity.

Symptoms of the infection are characterized by the emergence of distinctive cup-shaped apothecia. These structures are deep black on the outside with a reddish or olive-black interior. They usually cluster on wood or mossy surfaces near the base of trees, serving as visible evidence of the fungal activity within the host’s proximity.

Effective management requires strict sanitation practices to limit the spread of fungal spores. Protective measures include

• prompt removal of infected woody debris;
• avoiding mechanical damage to the tree bark;
• maintaining good air circulation around the plants;
• reducing excess soil moisture.