Phellinus parmastoi

Phellinus parmastoi is a pathogenic wood-decay fungus belonging to the Hymenochaetaceae family. It is primarily known for causing white rot in the trunks of various deciduous trees, leading to the gradual degradation of both lignin and cellulose within the host plant's internal structure.

The host range of this fungus typically includes hardwood species, with a particular preference for aspen, birch, and poplar. It enters the tree through wounds, fire scars, or branch stubs, establishing its mycelium within the heartwood and eventually expanding its destructive activity into the sapwood.

Visible symptoms include the appearance of perennial, woody fruiting bodies on the trunk surface. These brackets are often hoof-shaped or resupinate, with a dark, cracked surface. When infected wood is examined, it displays typical white rot, characterized by a bleached appearance and a soft, fibrous texture that loses structural integrity over time.

The fungus thrives in environments with high humidity and limited air circulation. Spore dispersal is primarily mediated by wind, allowing the pathogen to infect other susceptible hosts in the vicinity. The fungal development is highly dependent on the tree's health; stressed trees are significantly more susceptible to colonization compared to vigorous, healthy individuals.

The ecological and economic impact of Phellinus parmastoi is substantial, as it leads to timber degradation and hazardous tree failure. Preventive measures must focus on minimizing wounding, maintaining forest sanitation by removing highly infected trees, and applying protective treatments to pruning wounds to prevent entry points for the fungal spores.