Described from a collection made in Berkeley, California, USA (Gilkey 1916).

Genetic studies by Smith et al. (2006) suggested the possibility of five cryptic phylogenetic species in the Genea harknessii complex. Smith et al. (2006) stated; “Despite significant diversity in the ITS, mature ascomata from three of the G. harknessii lineages could not be morphologically differentiated”.

Genea harknessii is a small dark brown, dark reddish brown to blackish, wrinkled and folded hypogeous fungus, with a warted surface. The interior is convoluted with irregular hollows from in-folded and lobed walls, with a similar color and texture to the exterior. The thin, fragile walls have whitish to grayish flesh.

Currently known from ~35 sites in the Pacific Northwest and California, but these records include all species in the Genea harknessii phylogenetic complex. Smith et al. (2006) suggested the possibility of five cryptic phylogenetic species in the Genea harknessii complex. Until such time that species constraints are delimited, this species (complex) should be listed as Data Deficient (DD).

Widespread in coastal, foothill and montane forest, from central California into Washington, USA. However, Genea harknessii is a complex of cryptic phylogenetic species (Smith 2006), and it’s unknown which species occurs where.

Although rarely collected, it’s probably more of a case of being overlooked. The fruit bodies are small, buried in duff and are dark colored, making them especially hard to detect, even when one is actively looking for them. Reports come from a widespread area; the southern portion of the reported range is from the central California Coast, and southern Sierra Nevada, north into Washington. But, being a complex of cryptic phylogenetic species, it is currently unknown if the same species occurs across the reported range.

Hypogeous, solitary or scattered, buried under leaves, in duff or soil. Ectomycorrhizal; most collections come from forest or woodlands with oaks (Quercus spp.). Also with Douglas-fir (Pseudotsuga menziesii), fir (Abies spp.), and Madrone (Arbutus menziesii). Fruiting from late fall into early summer; winter and early spring specimens typically don’t have mature spores.

Loss of habitat due to development and urban sprawl in coastal forest and in the Sierra Nevada Foothills.

Targeted surveys for this species, and additional work delimit species concepts, and range of said species within this complex.

Gilkey, H.M. 1916. A revision of the Tuberales of California. University of California Publications in Botany 6:275–356.

MyCoPortal. Mycology Collections Portal. Available at: http://mycoportal.org

Siegel, N., Vellinga, E.C., Schwarz, C., Castellano, M.A. and Ikeda, D. 2019. A Field Guide to the Rare Fungi of California’s National Forests. Bookmobile: Minneapolis, MN. 313 p.

Smith, M.E., Trappe, J.M. and Rizzo, D.M. 2006. Genea, Genabea and Gilkeya gen. nov.: ascomata and ectomycorrhiza formation in a Quercus woodland. Mycologia 98(5): 699–716.