Phaeolus schweinitzii
Species of fungus
From Wikipedia, the free encyclopedia
Phaeolus schweinitzii, commonly known as velvet-top fungus, dyer's polypore, dyer's mazegill, or pine dye polypore, is a fungal plant pathogen.
| Phaeolus schweinitzii | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Polyporales |
| Family: | Phaeolaceae |
| Genus: | Phaeolus |
| Species: | P. schweinitzii |
| Binomial name | |
| Phaeolus schweinitzii (Fr.) Pat. (1900) | |
| Phaeolus schweinitzii | |
|---|---|
| Mycological characteristics | |
 | Pores on hymenium |
 | Cap is offset |
 | Hymenium is decurrent |
 | Stipe is bare |
 | Spore print is white to yellow |
 | Ecology is saprotrophic or parasitic |
 | Edibility is inedible |
Taxonomy
P. schweinitzii is named after Lewis David de Schweinitz, a Pennsylvania-born Moravian minister and important early American mycologist.
Description
P. schweinitzii is a polypore, although unlike bracket fungi the fruiting body may appear terrestrial when growing from the roots or base of the host tree.[1][2]
The fruiting bodies, appearing in late summer or fall, commonly incorporate blades of grass, twigs, or fallen pine needles as they grow.[3] They are tannish with darker brown centres, with orange to pale margins on young specimens.[1][4] They may grow beyond 25 centimetres (10 in) in diameter.[4] As the fruiting bodies age, the pore surface turns from yellow to greenish yellow, the top becomes darker, and the yellow-brown flesh becomes harder and more wood-like.[3] The pores bruise brown.[1] The spores are white, elliptical, smooth, and inamyloid.[4]
The effect, impact and significance of infection by this fungus is rooted in the fact that it causes brown rot, which degrades the cellulose. Thus there is a loss of tensile strength which often leads to brittle fracture near the stem base, even at a fairly early stage of decay. Decay initiated above ground can lead to branch snap or breakout.[5]
Similar species
Similar species include Heterobasidion irregulare, H. occidentale, Inonotus dryophilus, and Onnia tomentosa.[4]
Habitat and distribution
P. schweinitzii causes butt rot on conifers such as Douglas-fir, spruce, fir, hemlock, pine, and larch.[6] It is native to North America and Eurasia,[6] and has been identified as an exotic species in New Zealand, Australia, and South Africa.[7]