Scutellospora rubra is a new arbuscular mycorrhizal species trapped in a pot culture of rhizosphere soil from Eucalyptus dunnii. Spores
are dark red-brown, 140–220 μm diam., and closely resemble those of S. heterogama in size, colour, and subcellular organization, but
the outer layer of the spore wall is smooth rather than ornamented. Resolution of such species-level variation to properties of the
spore wall is consistent with that measured among all other species of arbuscular mycorrhizal fungi studied to date.