A–I. Septoglomus altomontanum (ZT Myc 30432 and 30433). Spores are dark reddish-black (A) to dark reddish brown (B, C), often oval to ellipsoid, with two wall layers (SWL1 and SWL2) (D, E). Subtending hyphae regularly lighter in colour than spores (F, G), and cylindrical (A, C, F), and frequently recurved (B, G–I). They are regularly widest at spore base and at some distance from the spores, while they are about 3–5 µm thinner in between and taper to 8–13 µmm at further distances (approx. 35–130 µm) from the spore base. The pores at the spore base are generally closed by a thick septum (sp) (F, G–I).