Pseudorhizina californica Psilocybe
Cap lobed to saddle-shaped, relatively broad, 5.0-12.0 (16) cm when full expanded; margin incurved to occasionally decurved, free from the stipe; surface consisting of shallow bumps and depressions, more or less glabrous, grey-brown, medium-brown, to olive-brown; sterile undersurface cream-colored, minutely tomentose; context thin, < 1 mm, cream-colored; odor and taste not determined.
Stipe 4.0-8.0 cm long, 2.0-4.0 cm thick, more or less equal, deeply fluted, the ribs forming the underpinnings of the cap; surface cream to pale-yellow, tomentose, often with a waxy aspect, flushed pinkish towards the base.
Spores 13.0-18.0 x 8.0-10.5 µmmicrons, ellipsoid, smooth, thin-walled, some with small polar guttules or granules of varying size; spore deposit not seen.
Solitary or in small groups in conifer woods; fruiting in humus or on rotting wood in moist areas, e.g. seeps, edges of creeks and marshes etc.; low to mid elevations of the Sierra Nevada and Coast Ranges; fruiting from late spring to early summer; uncommon.
Toxic according to some accounts.
With a broad, olive-brown to grey-brown cap and pinkish, ribbed stipe, Pseudorhizina californica is one of prettiest and distinctive false morels. It occurs commonly in the Pacific Northwest, but sparsely in California. This false morel was historically placed in Helvella, and more recently in Gyromitra. Harmaja (1976), transferred it to Pseudorhizina citing a number of morphological and chemical differences, the most obvious being a ribbed cap with a tomentose undersurface, pinkish stipe, and smaller spores with oil drops that are variable in size and number. Recent DNA evidence supports Harmaja's transfer. Pseudorhizina sphaerospora of Eastern North America is very similar, differing as the species suggests, by globose spores.