COLOR: Completely hyaline (sparkling white) when mature.

SHAPE: Mostly globose, subglobose, but also ellipsoid to ovoid.

SIZE DISTRIBUTION: 50-80 µm, mean = 64 µm (n = 102)

SPORE WALL: Consisting of three hyaline layers (L1, L2 and L3), all of which exhibit some flexibility in broken section. As a result, the spore wall contains numerous folds from any or all of the layers.

In PVLG		In PVLG & Melzer's reagent

L1: A thin hyaline layer, < 1 µm thick, which is continuous with the wall of the neck of the sporiferous saccule. This layer often separates somewhat from the inner two layers and sometimes sloughs completely with loss of the saccule.

L2: A thin hyaline layer, < 1 µm thick, which usually is adherent to the innermost layer (L3). It has distinct margins that resolve it's discrete structure; in some spores it may separately slightly from L3.

L3: A thicker hyaline layer than either L1 or L2, ranging from 1.3-4 µm thick, which together with L2 form an endospore which encloses the spore contents.

Cicatrix proximal to saccule is 7-10 µm in diameter, with a very thin < 1 µm ridge. The smaller distal cicatrix rarely is seen to measure (usually attached hypha is absent and there is no defining detail by which to find it).

COLOR: Hyaline.

SHAPE: Mostly subglobose, occasionally ellipsoid

SIZE DISTRIBUTION: 50-70 µm, mean = 59 µm.

SACCULE WALL: One layer, sometimes with an outer coating of granular material, < 0.5-1.0 µm.

DISTANCE FROM SACCULE TO SPORE: 10-30 µm.

Yet to be examined. However, Sieverding and Toro (1987) indicate that fungal structures stain only faintly, and thus likely bear similarity to mycorrhizae of fungal species in Archaeosporaceae (non-Acaulosporaceae saccule-forming fungi).

When spores float in water after extraction, the saccule often is oriented downward so that it is not always easy to detect, much like that of Archaeospora trappei. When saccules are absent, spores are almost impossible to distinguish from Ar. trappei under a dissecting microscope. When remnants of the saccule neck are present (suggestive of a subtending hyphae), then spores are easily mistaken for Paraglomus occultum.

Entrophospora schenckii is the only species in the genus which does not appear to have a germinal wall. In fact, subcellular structure is very similar to that of Ar. trappei. Given similarities in morphology (spores and mycorrhizae), work currently is underway to examine small subunit rDNA sequences and determine relatedness of these two species in both mycorrhizae and spore morphology.

Sieverding, E. and S. Toro. 1987. Entrophospora schenckii: A new species in the Endogonaceae from Colombia. Mycotaxon 28:209-214.