Hydnum ferruginescens Swenie & Matheny

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 ferruginescens Swenie & Matheny sp. nov. Figs 3D, 5G

Diagnosis.

Most closely related to the Eurasian Hydnum magnorufescens but differs from it by somewhat smaller basidiospores, ITS sequence divergence, and geographic distribution in the southeastern U.S.

Type.

UNITED STATES. North Carolina: Buncombe County, Tanbark Ridge (35.6535; -82.4853), growing singly or conjoined in moss along trail with Pinus strobus , Quercus prinus , Kalmia latifolia , 915 m, 4 Sep 2016, M. Hopping MH16005 (holotype: TENN 073549).

Etymology.

ferruginescens (L.), becoming ferruginous or rust-colored, in reference to the overall coloration of this species.

Description.

Pileus 22-60 mm wide, round, convex, becoming depressed; margin incurved and entire when young, then irregularly lobed or degraded in age; surface dry, glabrous, tawny to fulvous (5YR 5/8 to 6/8), discoloring slightly darker when handled. Spines 1-4 mm long, shorter near the margin, adnate to subdecurrent, white to cream (5A2-A4), bruising orange. Stipe 15-40 × 5-12 mm, central or eccentric, equal or slightly wider at apex, texture smooth, white or cream, lightly bruising orange (7.5 YR 7/8, 5A6-7); thick white mycelial mat sometimes present at base of stipe. Context white, unchanging after 5 minutes where cut in half. Odor not distinctive. Taste not distinctive or mildly fruity.

Basidiospores (5.5)6 –6.9– 8 μm × 5 –6.3– 7.5 μm, Q=1.01 –1.09– 1.22, (n=45/2), globose to subglobose, smooth, hyaline in KOH. Basidia 39-56 × 7.5-9 μm with (3)4-5 sterigmata. Pileipellis an interwoven cutis, hyphae smooth, cylindrical, thin-walled, mostly 5-7 μm wide. Clamp connections present.

Distribution.

Southeastern U.S. - North Carolina (type), Tennessee, Arkansas (GenBank KX358033).

Ecology.

In mixed woods with Quercus , Pinus , Carya , Tsuga . September.

Other specimens examined.

UNITED STATES. Tennessee: Big South Fork National River & Recreation Area, West Bandy Trail, scattered along trail with Quercus , Carya , Pinus , Tsuga , 450 m, 23 Sep 2017, R.A. Swenie RAS229 (TENN 073061).

Discussion.

Hydnum ferruginescens is known only from three occurrences in the southeastern U.S. This species is similar to H. magnorufescens , which has similarly sized basidiomes but slightly larger spores and is known from Europe and Asia.