Truffle Genus: Melanogaster

Melanogaster tuberiformis basidiospore scale = 10 µm

Kingdom: Fungi Phylum: Basidiomycota Order: Boletales Family: Paxillaceae

Spore Characters

Surface: Smooth.
Shape and Size: Longitudinally symmetrical, ellipsoid to ovoid, obovoid, fusoid, ventricose, or subcitriform, 6-22 x 3.5-13 µm, with a truncate base.
Wall: 1-2 layered, 0.5-1.5 µm thick.
Color in Water: Pale brown to dark brown, purple-brown, dark purple, or nearly black.
Melzer's Reaction: Not distinctive.
Comments: The dark brown or purple pigmentation of the spores of most Melanogaster species is distinctive among the smooth-spored truffle fungi. Spores of species in the mushroom genus Coprinus may resemble those of Melanogaster, but usually show an apical pore; Melanogaster spores have no apical pore.

View photos of Melanogaster spores

Sporocarp Characters

Shape and Size: Globose, ellipsoid, or irregular, 1-6 cm in diameter, with some species occasionally reaching up to 10 cm.
Peridium: Dark brown to brown-black, felty, usually with robust rhizomorphs appressed onto the bottom and sides.
Gleba: Brown to black gel-filled chambers, separated by white, pale yellow-brown, or yellow chamber walls.
Odor: Fruity to garlicky or nauseous sweet-oily.

View photos of Melanogaster sporocarps

Name Derivation

Named by German naturalist August Karl Joseph Corda (1809-1872) (1831) rom Greek, melano- (black), and -gaster (literally "stomach" but in mycology, generally referring to Gasteromycetes, i.e. puffballs), hence "black puffball" in reference to the black gleba common to most species. It is not a puffball, however; the gleba is gelatinous rather than powdery.

Distribution

Northern Hemisphere in association with ectomycorrhizal conifers and hardwoods from sea level to high elevation forests. Introduced into the Southern Hemisphere on roots of ornamentals such as oaks.
Season: Most species fruit either in spring or in autumn, but sporocarps of some species can be found throughout the year except in very dry or cold weather.
Species known from North Temperate Forests: About twenty.

Keys and Descriptions

No recent treatments of the genus have been published. The most comprehensive treatments and keys are those of Zeller and Dodge (1936) in English and Svrcek (1958) in Czech and Latin. A new world monograph of the genus is badly needed.