Morchella importuna

Description

Morchella importuna is a species of fungus in the family Morchellaceae described from North America in 2012. It occurs in gardens, woodchip beds, and other urban settings of northern California and the Pacific Northwest region of the United States and Canada. The fruit bodies develop a distinctive ladder-like pattern of pits and ridges on the surface of their conical caps.

The species is also often found in disturbed environments, such as areas destroyed by forest fire, where it may feed off the burnt plant matter and help with decomposition.

The fungus has also been reported from Turkey, Spain, France, Switzerland, Canada and China, although it is unknown whether this is a result of accidental introductions. It is considered a choice edible mushroom.

Common names: Black Landscape Morel.

Mushroom Identification

1. Ecology

   Clearly saprobic when growing in tree-less environments, but perhaps potentially mycorrhizal in other locations; limited to landscaping sites, gardens, planters, and so on; March through May; distributed primarily from California and Nevada to British Columbia.

2. Cap

   3-15 cm tall and 2-9 cm wide; conical or nearly so, but occasionally egg-shaped or nearly round; pitted and ridged with distinctively deep, vertical channels and regular, ladder-like cross-ridges; when young with bald or finely velvety, bluntly rounded, grayish to brownish ridges and similarly colored pits; when mature with sharpened or eroded, dark brown to black ridges and brown to olive or yellowish-brown pits; attached to the stem with a small groove (2-5 mm deep); hollow.

3. Stem

   3-10 cm high and 2-6 cm wide; usually becoming somewhat swollen at the base; whitish to pale brownish; bald or finely mealy with granules; hollow.

4. Microscopic Features

   Spores 18-24 x 10-13 µ; smooth; elliptical; without oil droplets; contents homogeneous. Asci 8-spored. Paraphyses cylindric with variable apices; septate; hyaline in KOH. Elements on sterile ridges 125-300 x 10-30 µ; septate; hyaline to brownish in KOH; terminal cell cylindric with a subclavate, clavate, subcapitate, or subfusiform apex.

5. Similar Species

   The rare Pacific Northwest morel Morchella hotsonii, known only from its type collection, is quite similar in appearance to M. importuna. The former species is distinguished by its finely velvety surface.

History

Officially described in 2012, Morchella importuna was one of 14 new North American species that resulted from the Morel Data Collection Project. The type locality was in King County, Washington. It was previously identified as phylogenetic species Mel-10 in a 2011 publication, and erroneously as the "Classic North American Black Morel" in 2005, where it was lumped together with Morchella angusticeps, and what has since been described as M. brunnea. The specific epithet importuna, which means "inconsiderate" or "assertive", refers to the morel's habit of causing "consternation and distress among gardeners and homeowners whose territory has been invaded".

Synonyms

1. Morchella vaporaria Bartayrès ex Brond., Cryptog. Agenais, 3: 33 (1830), fide Richard et al. (2015).

2. Morchella hortensis var. vaporarius (Brond.) Boud., Bull. Soc. mycol. Fr., 13: 146 (1897).

3. Morchella hortensis Boud., Bull. Soc. mycol. Fr., 13: 145 (1897), fide Richard et al. (2015).

Photo sources:

Photo 1 - Author: BlueCanoe (CC BY-SA 3.0)

Photo 2 - Author: Tim Sage (CC BY-SA 4.0)

Photo 3 - Author: Lukas from London, England (CC BY-SA 2.0)

Photo 4 - Author: Tim Sage (T. Sage) (CC BY-SA 3.0)