Truffle Genus: Glomus
 Glomus macrocarpum glomeromycospore |
Kingdom: Fungi Phylum: Glomeromycota Order: Glomerales Family: Glomeraceae |
Spore Characters
Surface: Smooth to roughened or ornamented with spines or warts or enclosed in a mantle of adherent hyphae.
Shape and Size: Globose to ellipsoid or pyriform, when smooth 20-310 x 18-305 µm, when ornamented or mantled by adherent hyphae 105-452 x 169-470 µm (excluding ornamentation of adherent hyphae).
Wall: One to 3-layered, 2-18 µm thick (excluding ornamentation of adherent hyphae).
Color in Water: Hyaline to yellow-brown or brown-black.
Melzer's Reaction: Not distinctive in most, but distinctive in some.
Comments: Many Glomus spp. fruit as individual spores in soil and are not usually eaten by mammals. Only sporocarpic species are included in the range of characters outlined in the keys. Spores of all species form at the tip of a hyphae, a trait that is distinctive among hypogeous fungi to Glomus. Glomus species generally have broadly ellipsoid to globose spores borne randomly or in rows within the sporocarp.
View photos of Glomus spores
Sporocarp Characters
Shape and Size: Globose to convoluted or irregular, 3-20 mm broad.
Peridium: Absent, or when present white to yellow or brown, smooth to felty to cottony.
Gleba: White to bright yellow or brown, containing spores randomly placed or aligned in rows radiating from the base.
Odor: Not distinctive.
View photos of Glomus sporocarps