Truffle Genus: Pachyphloeus

Pachyphloeus melanoxanthus ascospore scale = 10 µm Pachyphloeus saccardoi ascospore scale = 10 µm Pachyphloeus saccardoi ascospore scale = 10 µm Pachyphloeus tessalatus ascospores

Kingdom: Fungi Phylum: Ascomycota Order: Pezizales Family: Pezizaceae

Spore Characters

Surface: Ornamented with free or mucilage-embedded warts or spines 1-3 µm tall.
Shape and Size: Globose, 14-21 µm in diameter, excluding ornamentation.
Wall: Single, 1-2 µm thick.
Color in Water: Hyaline to brown.
Melzer's Reaction: Not distinctive.
Comments: Spores of Pachyphloeus are not easily separated from those of Sphaerosoma spp. Young spores of Choiromyces meandriformis or Sphaerozone ostiolatum can also be confused with the warty-spored Pachyphloeus species. In Melzer's reagent, the asci of some Pachyphloeus spp. appear faintly green or blue-green.

View photos of Pachyphloeus spores

Sporocarp Characters

Shape and Size: Subglobose, often with an apical cavity or cluster of grooves.
Peridium: Green-yellow to red-brown or black, scabrous to coarsely verrucose.
Gleba: Yellow to nearly black, marbled with pale veins that tend to converge near the sporocarp apex, solid.
Odor: Not distinctive to pungent.

View photos of Pachyphloeus sporocarps

Name Derivation

Named by French botanist and mycologist Louis René Tulasne (1815-1885) and his younger brother French physician and mycologist Charles Tulasne (1816-1884) (1845) from Greek, pachy (thick) and -phloe (bark) in reference to the thick peridium of the sporocarps.

Distribution

Europe, North America, Japan, and some undescribed species from Australia and South America.
Season: Spring and autumn.
Species known from North Temperate Forests: Six.

Keys and Descriptions

Gilkey (1954) for North American species, Hawker (1954) and Lange (1956) for European and Japanese species. Montecchi and Sarasini (2000) also covers Europe.