Acaulospora sporocarpia

Whole Spore

This description is a combination of information obtained from the protologue (Rothwell and Trappe, 1979), type specimens, and universal patterns of morphological organization and structure in Acaulosporaceae. This species was described from herbarium specimens and has yet to be characterized from healthy living tissue.

Sporocarps irregular, dark-brown, up to 2.5×1.5×1.5 cm, composed of spores that appear black in incident light, plus sporogenous saccules, hyphal swellings, hyphae and debris.

Spores formed laterally on hypha subtending a single sporiferous saccule. Spores ellipsoid, broadly fusiform, subglobose,or globose, (140-) 160-200 (-240) x (125-) 150-175 (-200) µm diam, dark brown or black, borne on a single pedicel branching from the neck of the saccule.

Drawing of saccule and spore budding from saccule neck
Saccule and spore budding from saccule neck

Subcellular Structure of Spores

The spore wall is composed of two separable groups: the outer consists of a single wall (wall 1), dark reddish brown in transmitted light, 2.5-5 um thick, laminate, with a rough outer surface; the inner consists of a single wall (wall 2), hyaline, 7-15 µm thick, tough, laminate, and sometimes separating into 2 or more layers when crushed.

Spore subcellular structure (in PVLG)
Spore and sacculeIw1 in pvlgSpore wall iw1
Spore subcellular structure (in Melzer’s reagent)
In melzers reagent spore wall dark dark red and iw1 redSporea and saccule 2L1 and L2 of iw1

 

Pedicel

The pedicel is continuous with hypha that subtends the sporiferous saccule, may be persistent, brown, up to 40 µm long and 20-30 µm wide at the point of attachment to the spore.

Reference

  • Berch, S. M. 1985. Acaulospora sporocarpia, a new, sporocarpic species, and emendation of the genus Acaulospora (Endogonaceae, Zygomycotina). Mycotaxon 23:409-418.