| Macroscopic characters | shape | Dimidiate to long; narrow and shelf-like; imbricate or single |
| size | Up to 9 x15 x 5 cm |
| texture | Corky to leathery |
| pileus | Becoming incrusted; brown; blackish with age; tomentose to glaborus |
| stipe | N/A |
| context | Ivory; corky; azonate up to 1 cm thick |
| pore surface | Ivory white to pinkish cream |
| pores | Circular to angular; 4-5 per mm |
| tube layer(s) | Up to 3 mm long each year; concolorus and continuous with context |
| Microscopic characters | hyphal system | Dimitic |
| clamp connections | N/A |
| sterile elements | N/A |
| basidiospores | Subglobose to ovoid; hyaline; minutely echinulate at 1000x; 4.5-6.5 x 3.5-8 um |
| Habitat characters | substrate/host | Living and dead conifers |
| seasonality | Annual; occasionally perennial (up to 3 years) |
| type of decay | White pocket rot of the roots and butt of living conifers; pathogenic on living sapwood causing mortality and windthrow of infected trees |
| range | Throughout the coniferous forests of northeastern and southeastern U.S. and Appalachian Mountains; in western North America from Alaska to Mexico, but not common in the central Rocky Mountain Range. |
| Notes | One of the major root rot pathogens on North American conifers. Cream pore-surface reacts strongly with Melzer’s reagent. |
| References | Overholts, 1953; Gilbertson & Ryvarden, 1986. Grand & Vernia, 2007. |
