Summary:
Byssoporia terrestris is recognized by the soft and variously colored pore surface growing flat on conifer wood, and the nearly round, slightly thick-walled spores. The colors may be white, cream, yellow, orange, red, pink, purple, blue, or blue-green. The description is derived from Larsen & Zak except where otherwise indicated. They have described several varieties: 1) lilacinorosea (pore surface white to cream with stains rose, bright red, pale pink, or deep brick orange, surface hyphae of rhizomorphs with noticeable staghorn branching, rhizomorphs white and appearing coated with fine crystals), 2) sartoryi (fruitbody white, with parts of fruitbody and rhizomorphs stained blue-green, blue, or purple, surface of rhizomorphs composed of thick-walled curly hyphae), 3) aurantiaca (fruitbody white, parts stained orange, rhizomorphs without clamp connections and white sometimes with small orange stains, becoming uniformly cream to dull yellow), 4) sublutea (fruitbody cream becoming pale dull coral or with parts dull coral, rhizomorphs with clamp connections, sulphur yellow to pale coral, subicular hyphae not inflated at septa), and 5) parksii ("Basidiocarps with pore surfaces pale yellow and parts with orange stains, uniformly deep yellow orange when dry, some areas stained brown, with the underside of the subiculum yellow with occasional orange stains and finally drying distinctly yellow", rhizomorphs with clamp connections and "watery pale yellow with spotty orange stains and may become uniformly bright orange as they age", subicular hyphae inflated at septa).

Microscopic:
spores 4-5 x 3-3.5 microns, broadly elliptic to nearly round, less frequently round, inamyloid, colorless, with wall thickening apparent, obliquely apiculate; basidia 4-spored, 15-25 x 5-6 microns, clavate, without clamp, transversely septate at base; hyphal system monomitic: subicular hyphae 2-3(4.5) microns wide, "sparsely to densely encrusted with granules, septate, clamp connections infrequent, sometimes inflated at the septa", rhizomorphs with core or central hyphae 2.5-11 microns wide, with or without clamp connections, surface hyphae 1.5-3 microns wide, thin-walled to thick-walled, with or without encrustation, straight, curly, spiral, or staghorn-like, trama hyphae 2-4.5 microns wide, "similar and continuous with the context", thin-walled, septate, clamp connections absent

Spore Deposit:
white (Buczacki)

Notes:
Byssoporia terrestris has been found in BC, WA, OR, ID, AB, AZ, CA, CO, MT, NC, NJ, PA, and WY, and circumglobally in the warm and temperate zone, (Gilbertson).

Synonyms and Alternate Names:
Byssocorticium terrestre (DC.: Fr.) Bondartsev & Singer
Gyromitra bubacii Velen.
Helvella esculenta Pers.: Fr.
Polyporus terrestre DC.: Fr.
Poria parksii Murrill