The
cap is 15–55 mm diam., broadly
conic, expanding to broadly
umbonate to more or less flattened, with edges becoming slightly upturned and often splitting; dry; lacking
veil remnants; dark brown to yellow-brown, striate (radially lined) to edge,
hygrophanous, drying to pale yellow-brown to straw-coloured; staining greenish-blue with damage or age; flesh white. The gills are adnate (broadly attached to the stem), close, greyish yellow-brown, maturing dark violaceous, with a conspicuous pale narrow margin. The
stipe is 35-100 x 1.5–5 mm, cylindric, finely
pruinose in the upper part and silky-fibrillose near the base, white, yellow or pinkish purple brown, with brownish flesh.
Veil cortinoid and poorly developed, disappearing as caps mature. All parts staining deep greenish-blue or blackish-blue with damage.
Spore print violet brown.
Spores measure (6.5-)7-9.5 x 4–5.5 x 3.5-4.5 μm, 8.1 x 4.9 x 4.3 μm average, ovate in face view, elliptic-ovate in side view; brown-walled and smooth, 0.5 μm thick with apical pore;
Basidia 20-28 x 4.5-6 μm, cylindric, with 4 spores, clamped;
Cheilocystidia 15-32 x 4-8 μm, ventricose-rostrate (swollen and uneven with a beak), with long, tapering, flexuous and sometimes bifurcate neck (forked in two), transparent, thin-walled, up to 12 μm long;
Pleurocystidia 13-19 x 4.5-6 μm, scattered, similar to cheilocystidia but with shorter neck, up to 4.5 μm.
Similar species Psilocybe zapotecorum in
Mexico and
South America, as noted by Guzman et al. (1991), "
P. aucklandii is very similar to
P. zapotecorum R. Heim emend. Guzman, which is common in Mexico and known from South America. The two species are barely distinguishable microscopically, although comparison with published descriptions (Guzman 1983) show that
P. aucklandii may have slightly narrower pleurocystidia and slightly wider spores. Published illustrations
of P. zapotecorum (Guzman 1983) appear to show that
P. aucklandii is a less robust species." == Distribution and habitat ==