Belonging to the family Corticiaceae, Galzinia incrustans is a "true" crust fungus. This species appears to be fairly common in Northeastern North America with over 30 collections represented in MyCoPortal. In Scandinavia — the region with the greatest attention to fungal conservation — studies have found that fire restoration is important for maintaining wood-rotting fungal species diversity. G. incrustans is one such species that benefits from fire restoration. A few years after a burn event, G. incrustans is prevalent on charred wood (Olsson & Jonsson 2010).
The described specimen has an identical ITS sequence to that of the CBS fungal culture collection strain "CBS 172.36", which originates from Ontario, Canada. Given that this specimen was collected in Massachusetts, the similarity of these specimens' ITS rDNA suggests to me that G. incrustans has a wide dispersal ability.
In Fungi Europaei Corticiaceae, the authors report various shrubs as substrates for G. incrustans. This specimen, however, was growing on another fungus — a conk. It is interesting to ponder whether this fungus was using the polypore as a leg up to better disperse spores, or whether the mycelium was actually digesting the polypore for nutrition. This specimen differs in other subtle ways from the description of Italian specimens, most notably in the color of the basidiocarp. This specimen is peachy salmon whereas that of the Italian specimens is reported as greyish.
Ecology: The described specimen was found on the first day of spring on March 21, 2017 on the undersurface of a conk.
Basidiocarp: Effused, fragile, ceraceous when fresh, pruinoise when dry; hymenial surface even to grandinoid; margin distinct, smooth to fimbriate.
Hyphal system: Monomitic, hyphae with clamps, thin-walled, hyaline, (1.8) 2.6–4.2 (4.3) µm wide (n = 10).
Basidia: Terminal, cylindrical to utriform, length (14.5) 17.2–29.5 (33) µm, width (3.4) 3.7–4.5 (4.6) µm, mean 23.3 ✕ 4.1 µm (n = 10), with four sterigmata and a basal clamp.
Basidiospores: Smooth, thin-walled, hyaline, inamyloid, indextrinoid, curved, narrowly cylindrical (cylindrical to allantoid), length (4.9) 5.2–6.0 (6.3) µm, width (1.5) 1.8–2.2 (2.4) µm, mean 5.6 ✕ 2.0 µm, Q (2.3) 2.5–3.1 (4.1) (n = 30), usually with one guttule, but sometimes none or two or more guttules.
Sterile Structures: Absent.
Sequences: ITS rDNA (MF289562 — 100% identical to Galzinia incrustans strain CBS 172.36).
Notes: Cyanophily was difficult to determine. The cytoplasm stained blue, but it is hard to tell whether the staining was sufficient to call this cyanophilous. All measurements were taken using a smash mount of dried tissue in 5% KOH stained with phloxine. Amyloidy was determined in Melzer's reagent. Cyanophily was determined in cotton blue.
MO329017, collection number BHI-F0664; collected on 21 March 2017 at Grape Island, Boston Harbor Islands National Recreation Area, Suffolk County, Massachusetts, USA, 42.2693°N 70.9218°W; legit. Alden Dirks & Lara Kappler, det. ITS rDNA, conf. Alden Dirks, ref. Bernicchia & Gorjón (2010); Farlow Herbarium——.
Bernicchia, A. & S.P. Gorjón. (2010). Corticiaceae s.l. Fungi Europaei n˚12. Ed. Massimo Candusso, Italia.
Olsson, J., & Jonsson, B. G. (2010). Restoration fire and wood-inhabiting fungi in a Swedish Pinus sylvestris forest. Forest Ecology and Management, 259(10), 1971–1980.
Galzinia incrustans collected at Grape Island, Boston Harbor Islands National Recreation Area in March, 2017.
The fungus was growing on the pore surface of a polypore.
Note the spreading white margin of Galzinia incrustans and the bumpy texture.
The basidia have a basal clamp and are variable in shape; some seem to be pedunculate, or stalked.
Galzinia incrustans has curved basidiospores with usually one, sometimes none, or two or more guttules.