Hydnum canadense 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 canadense Niskanen & Liimat., Mycologia 110: in press (2018) Figs 3G, 5I

Type.

CANADA. Newfoundland and Labrador: Near Grand Falls, south of the Exploits River, west of Hwy 360, south of Hwy 1, along a gravel road beside Moccasin Lake (48.9030; -55.5580), in conifer-dominated forest, 9 Sep 2009, K. Liimatainen & T. Niskanen 09-006 (holotype H7043727, isotype K(M)248978, isotype NY).

Description.

Pileus 12-25 mm wide, irregularly round to slightly reniform, convex to plano-convex, surface dry, glabrous, orange ("Zinc Orange" to "Xanthine Orange"), sometimes cracking in age near central depression; margin incurved and entire or slightly degraded. Spines 1-3 mm long, adnate, cream-colored, at times thick and somewhat flattened. Stipe 15-35 × 5-8 mm, central or eccentric, equal or widening at base, firm, smooth, white to cream, lightly staining ochre to medium brownish orange ("Mars Yellow" to "Orange Rufous") where handled. Context not observed. Odor and taste mild.

Basidiospores 7 –8– 9(9.5) μm × 7 –7.6– 9 μm, Q=1.00 –1.05– 1.11, (n=38/1), globose to subglobose, smooth, hyaline in KOH. Basidia 38-46 × 7.5-9.5 μm with 3-5 sterigmata. Pileipellis an interwoven cutis, hyphae smooth, cylindrical, thin-walled, mostly 5-7 μm wide. Clamp connections present.

Distribution.

Eastern North America - Newfoundland and Labrador (type, GenBank KX388681) and North Carolina.

Ecology.

In conifer forest with Abies fraseri . August to September.

Specimen examined.

UNITED STATES. North Carolina: Yancey County, Mount Mitchell State Park, in fir forest, 2000 m, 19 Aug 2016, R.A. Swenie RAS100 (TENN 073010).

Discussion.

Hydnum canadense is only known from high-elevation and higher latitude conifer forests in North Carolina and eastern Canada. The North Carolina collection was found among several basidiomes of H. umbilicatum . Hydnum canadense can be distinguished from H. umbilicatum by the 3-5 sterigmata (versus 2-4 sterigmata in H. umbilicatum ) and ITS sequence divergence. Hydnum canadense differs from the closely related H. mulsicolor by the association with conifers and larger spore size. Another closely related species, H. submulsicolor , is morphologically indistinguishable from H. canadense according to Niskanen et al. (2018), and ITS sequencing is likely necessary to reliably differentiate it from H. canadense . The spores of the North Carolina collection of H. canadense reported here are more globose with a lower average Q value than that of the Newfoundland and Labrador collections reported by Niskanen et al. (2018).