Hydnum vagabundum Swenie, Ovrebo & 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 vagabundum Swenie, Ovrebo & Matheny sp. nov. Figs 4B, C, 6F

Diagnosis.

Closely related to Hydnum subolympicum but differs from it by the paler, more lobate pileus and ITS sequence divergence.

Type.

UNITED STATES. Texas: Newton County, State Highway 87 and County Road 3062 (30.7080; -93.8270), scattered in soil under Fagus , Pinus , Quercus , 29 Dec 2011, C.L. Ovrebo CLO4985 (holotype: TENN 074443).

Etymology.

vagabundum (L.), wandering, roving about, in reference to the broad distribution of this species in North America.

Description.

Pileus 30-140 mm wide, round, convex, becoming plano-convex to broadly depressed; margin incurved and often lobed when young, then decurved or straight and wavy in age; surface matted tomentose or glabrous and pitted-grooved to bumpy in areas, off-white with pale pinkish buff tones (5A2), sometimes with slight ochre hues (5C4-C5), staining ochre where bruised. Spines 1-12 mm long, shortest near the pileus margin, adnate to subdecurrent, concolorous with the pileus or slightly darker pinkish-orange (5A3). Stipe 20-60 × 10-30 mm, central or eccentric, equal or with a swollen base, surface smooth or soft matted-tomentose, white or concolorous with the pileus, pinkish tan in areas, slowly staining ochre where bruised. Context solid, white, discoloring slight ochre (5C4-C5) where cut in half. Odor not distinctive. Taste mild or sweet-nutty, then slowly slightly acidulous.

Basidiospores 6.5 –7.4– 8.5 × 5 –6.1– 7.5 μm, Q=1.03 –1.22– 1.43(1.60) (n=97/4), subglobose to broadly ellipsoid, smooth, thin-walled, hyaline in KOH. Basidia 39-57 × 8-10.5 μm with (3)4-5 sterigmata. Pileipellis an interwoven cutis, hyphae smooth, cylindrical, thin-walled, mostly 3-7 μm wide. Clamp connections present.

Distribution.

Eastern U.S. and Central America - New York, Texas (type), Honduras (GenBank HM639267-HM639268).

Ecology.

In mixed woods with Fagus , Pinus , Quercus , Tsuga , Picea , Betula . May to December.

Other specimens examined.

UNITED STATES. New York: Bolton, Sand Lake, August, C.H. Peck (NYS-D-7819). Rensselaer County, Burden Lake, 1 Sep, C.H. Peck (NYS-D-7820). Tompkins County, Hammond Hill State Forest, Red Man Run Rd., on humus in mixed woods with Tsuga , Fagus , Picea , Betula alleghaniensis , 520 m, 1 Sep 2017, T.J. Baroni 10782TJB (CORT 014461).

Discussion.

Hydnum vagabundum is a large whitish species in subgenus Hydnum . Two collections of this species at NYS from the late 1800s and early 1900s were misidentified as H. albidum by Peck but feature distinctly larger basidiospores than the holotype of H. albidum . In addition, basidiomes of this species are much larger and fleshier than those of H. albidum . Partial ITS sequences obtained from Peck’s specimens match two extant collections from New York and Texas, as well as GenBank sequences from western Honduras (HM639268, HM639267; Sarmiento and Fontecha 2013). In Honduras this species can be found in May and June, where it is a common edible ( Sarmiento and Fontecha 2013). To date, H. vagabundum has the widest known range among the endemic eastern North American Hydnum species.

Peck’s notes of what is described here as H. vagabundum indicate it as a "white, edible Hydnum ". Another large whitish species, H. albomagnum , can be distinguished from H. vagabundum by the copious amount of leaf and needle debris that adheres to the pileus surface and smaller basidiospores.