Hydnum subolympicum Niskanen & Liimat., Mycologia 110: in press (2018)

Swenie, Rachel A., Baroni, Timothy J. & Matheny, P. Brandon, 2018, Six new species and reports of Hydnum (Cantharellales) from eastern North America, MycoKeys 42, pp. 35-72 : 35

Hydnum subolympicum Niskanen & Liimat., Mycologia 110: in press (2018) Figs 4A, B, 6E

= Hydnum repandum sensu Coker & Beers, 1951

Type.

CANADA. Newfoundland and Labrador: Near Humber Village, trail to Barry’s Lookout (48.9860; -57.7600), mature secondary growth of Betula papyrifera and B. alleghaniensis , also with Cantharellus amethysteus , 2 Sept 2012, A. Voitk 12.09.02.av12 (holotype DAOM744368, isotype K(M)249002).

Description.

Pileus 80-130 mm wide, round, convex, becoming plano-convex; surface dry, glabrous, dull reddish-orange when young (5 YR 5/6) then cream to peach or dull orange in age (5A2-3), sometimes cracking in age to reveal white color of flesh; margin incurved and entire, becoming wavy and decurved, staining ochre to rusty brown very slowly after handling ("Yellow Ochre" to 5B8). Spines 1-7 mm long, close, subdecurrent, cream-yellow to pinkish cream. Stipe 30-100 × 20-40 mm, central or eccentric, tapering downwards to a slightly bulbous base, texture firm, smooth, white or off-white, staining orange cream to rusty orange, then yellow-brown when handled ("Mars Yellow", 10YR 5/8). Context white to cream, dry, firm, brittle, discoloration not observed. Odor mild or fruity and reminiscent of apricots. Taste mild or slowly bitter or peppery.

Basidiospores 6 –7.5– 9 μm × 5 –6.1– 7 μm, Q=1.07 –1.23– 1.46 (n=38/3), subglobose to broadly ellipsoid, smooth, hyaline in KOH. Basidia 36-42 × 6.5-8 μm with (3)4-5 sterigmata. Pileipellis an interwoven cutis, hyphae smooth, cylindrical, thin-walled, mostly 4-6 μm wide. Clamp connections present.

Distribution.

Eastern North America - Newfoundland and Labrador (type), Quebec (GenBank No. KM406979), Maryland, Virginia, North Carolina, Tennessee, and Georgia.

Ecology.

In hardwood or mixed woods with Quercus , Betula . August to October.

Other specimens examined.

UNITED STATES. Georgia: White County, Unicoi State Park, Unicoi to Helen Trail, hidden in soil embankment under roots, 460 m, 16 Jul 2017, R. Healy RAS168 (TENN 073047). Maryland: Harford County, Susquehanna State Park, 60 m, 9 Sep 2016, RAS118 (TENN 073021). North Carolina: Buncombe County, Bent Creek Experimental Forest, Boyd Branch, solitary in mature bottomland forest including Liriodendron tulipifera , 670 m, 19 Sep 2016, M. Hopping MH16009 (TENN 073551). Tennessee: Great Smoky Mountains National Park, Schoolhouse Gap Trail, solitary in mixed woods under Quercus , 490 m, 26 Oct 2013, A.J. Ramsey AJR14 (TENN 073004). Virginia: Grayson County, Mount Rogers National Recreation Area, Mt. Rogers Trail, scattered along trail in mixed hardwood forest with Betula , Quercus , 1225 m, 17 Aug 2015, R.A. Swenie RAS029 (TENN 070845).

Discussion.

This eastern North American species is phylogenetically allied with H. repandum and relatives in subgenus Hydnum along with H. vagabundum sp. nov. (described below) and H. washingtonianum . It can be distinguished from European H. repandum mainly by the different geographic distribution (eastern North America). This species differs from H. vagabundum by the smooth yellow-peach pileus that tends to crack in age and mostly non-lobate pileus margin. In comparison to H. washingtonianum , H. subolympicum produces smaller spores. Because of the shape and coloration, basidiomes of H. subolympicum in the field can resemble large chanterelles from above. Like many other species of Hydnum , basidiomes of this species often possess the sweet apricot-like odor that is characteristic of chanterelles. In our experience, this species is a choice edible. Coker and Beers (1951) likely referred to this taxon under the name H. repandum .