[Given as accepted species in Index Species Fungorum. I have not yet located any molecular work .]
Quercus myrsinaefolia (Chinese evergreen oak) On living trunks (“Ad truncos vivos.”) by Ito & Otani, in Otani 1957 (Japan).
This was presented to be a new species based on:
1) Different habitat: on a live tree of this species; whereas H. erinaceus was said to fruit on dead trunks of other Quercus species and Castanopsis cuspidata.
2) Having a salmon-pink or light yellowish-orange color with yellow flesh; rather than “whitish, then yellowish” with white flesh in H. erinaceus.
3) Having a botyroidal growth form. “Compound tubercular mass 18×13 cm” compared to H. erinaceus’s “Simple tubercular mass 5–30 cm diam.”
4) Having shorter subulate spines., 5—10 mm long arranged all of the surface; H. erinaceus was said to have 10—60 mm long straight spines hanging downward and no spines on the upper surface.
5) Gloeocystidia cylindrical with capitate apex; gloeocystidia of H. erinaceus cylindrical or fusoid, not capitate.
6) Spores subglobose or ovoid 4.5–6.5 x 4.5–6 µm; compared to H. erinaceus having globose or ovoid 5.5–7 µm spores.
7) This taxa has also been commented upon for significance of having non-amyloid (hyaline to slightly flesh-colored) spores reported but it is also noteworthy that, in this same paper, Hericium erinaceus was similarly reported to show a hyaline reaction (non-amyloid) for its spores. AND it is also noteworthy that other workers have claimed a hyaline reaction for erinaceus spores (for example BCRC lists a hyaline reaction both for H. erinaceus and also for “H. ramosum”) suggesting there may be divergent approaches to staining or a possible misinterpretation of colors based on cultural color definitions?
Only point 5 is actually potentially significant as H. erinaceus can apparently share all of the other features.
Ito and Otani’s fungus seems most likely to be an immature H. erinaceus colored by adverse conditions of moisture and/or temperature.
Compare to Burdsall’s “Hericium erinaceum ssp. erinaceo-abietis”, or to Nikolaeva’s Hericium pytchogasteroides, or to our notes concerning an odd erinaceus encountered in Mendocino County. The latter has subglobose to ovoid spores up to 5.25 x 7 µm.
Hericium botyroides does not appear to have ever been collected a second time.