Helvella lacunosa is a common mushroom most often sighted in summer and fall, but occasionally observed in mid-winter in California. The common name for this species is the ‘Black Elfin Saddle’ mushroom. This is the first time we’ve seen it here, but it’s quite well camouflaged in the woods, so much so that I almost walked right by it!
Its dark coloration makes this mushroom difficult to spot, and the convoluted cap gives it the appearance of some other dried up piece of forest-floor debris, making it easy to miss. However, on close inspection, this seemingly uninteresting mushroom is actually quite beautiful.
This mushroom is most commonly found growing under pine and fir, singly or in small clusters, and is widely distributed across North America, Europe, China and Japan. Helvella lacunosa is also often seen in woodland clearings growing on burnt ground. The cap typically ranges from 1-10 cm, and is most often grey or black, however, white forms are occasionally seen.
This is not a gilled mushroom, and close inspection under the saddle-shaped or convoluted cap reveals a thin, friable cap, the margin of which may be attached to the stem at several points forming small chambers.
The stem is perhaps the most intriguing part of the Elfin Black Saddle mushroom. Growing up to 15 cm in length, when young, the stem color may be more off-white in coloration, darkening with age to grey or black. The hallmark features of this mushroom are that the stem is ornately ribbed with pockets (lacunae), and is quite unlike most other mushrooms you are likely to encounter.
Some report Helvella lacunosa to be edible when cooked, although the stems are not eaten. Others report that Helvellas are indeed at least mildly toxic. Most mycologists however do not recommend its consumption. To the untrained eye, Helvella lacunosa is similar in appearance to some forms of Gyromitra esculenta which is a potentially deadly false morel mushroom. Certainly a mistake not worth making…