Claroideoglomus Walker et al. (2007)

Spore Ontogeny

Development of spores proceeds exactly like that found in Glomus (Glomeraceae): by blastic expansion of a hyphal tip as shown below. Outer layer of the spore wall often sloughs as the spore ages (in soil or in pot culture storage). Developmentally, this layer is the first component of the spore wall to form in juvenile spores. Usually, organic material will accumulate on the surface; no reaction in Melzer’s reagent.

The hypha subtending the spore differentiates at the same rate and synthesizes the same component layers as that found in the spore wall. In some species the subtending hypha of mature spores is so thin that it is hard to see or separates from the spore.

Only two species have been discovered in this genus, both having been classified first as Glomus species (based on spore morphology). Faint to invisible mycorrhizal structures provide morphological clues of possible membership in this genus.