Helvella dryophila

What You Should Know

In the past, Helvella dryophila and Helvella vespertina were not known as separate species and were grouped under the name Helvella lacunosa, which is a European species that doesn't occur in North America. But recent DNA testing has revealed that there are at least 11 different species in the Helvella lacunosa 'group' in North America. Helvella dryophila is one of these species, found in North America and commonly associated with West-Coast oaks, especially coast live oak, during winter and spring. It resembles Helvella vespertina, which grows with conifers during fall and winter but is much larger in size. Identifying the mycorrhizal host trees is the best way to differentiate the two, but this can be difficult when both oaks and conifers are present in West Coast ecosystems. DNA sequencing is often the only reliable way to distinguish between the two species in such cases.

Helvella dryophila looks similar to H. vespertina, but the contrast in color between pileus and stem is striking; the pileus is very dark and squat and rounded with distinct well defined grooves when young, and the ascomata are up to 85 mm high.

This mushroom is edible when cooked but of poor quality.

Other names: Black Elvin Saddle.

Helvella dryophila Mushroom Identification

1. Cap

   The cap of this mushroom ranges from 0.59 to 1.77 inches (1.5 to 4.5 cm) in diameter and 0.79 to 1.38 inches (2 to 3.5 cm) in height. It is irregularly lobed and convoluted, and is typically black to dark gray in color. The cap is bald but wrinkled, and its margin is attached to the stem in several places. The undersurface of the cap is bald and gray to grayish brown.

2. Stem

   The stem measures 1.18 to 2.17 inches (3 to 5.5 cm) in length and 0.39 to 0.98 inches (1 to 2.5 cm) in thickness, and is more or less equal in shape. It ranges from grayish to dark gray in color, discoloring to a yellowish hue with age. The stem is deeply and ornately ribbed and pocketed, with ribs that have blunt edges. The basal mycelium of the stem is white.

3. Flesh

   The flesh of this mushroom is thin, brittle, and chambered. It is whitish to grayish in color.

4. Habitat

   This species is mycorrhizal with coast live oak and other oaks along the West Coast. It can grow alone, scattered, or gregariously. It is found from Oregon to southern California, extending eastward to the Sierra Nevada.

5. Microscopic Features

   Spores 15–20 x 10–13 µm; broadly ellipsoid; smooth; with one oil large droplet; hyaline in KOH and in water. Asci 200–250 x 7.5–10 µm; 8-spored. Paraphyses 200–275 x 2.5–5 µm; filiform, with rounded to clavate, subcapitate, or irregularly swollen apices; smooth; hyaline to brown, often with granular contents. Excipular surface a palisade of clavate, hyaline to brown terminal elements 15–20 x 5–12.5 µm.

Sources:

Photo 1 - Author: Nathan Gonzales (Public Domain)

Photo 2 - Author: Brittany Darwell (Public Domain)

Photo 3 - Author: P Holroyd (Public Domain)

Photo 4 - Author: LJ Moore-McClelland (Attribution 4.0 International)

Photo 5 - Author: Ken-ichi Ueda (Public Domain)