Summary:
Features include 1) relatively small, slender fruitbodies 2) a pale orange ochraceous to ochraceous cap that often has a distinct depression in the center, 3) non-decurrent to somewhat decurrent, whitish teeth that become pale ochraceous brown, 4) a relatively long, slender stem that is whitish but bruises very pale brownish ochraceous, 5) fruiting on the ground under conifers, and 6) spores that average 8.7-8.1 microns (Niskanen(10) for Hydnum cf. umbilicatum). The term Hydnum umbilicatum group could be used to include small, slender Hydnum species with ochraceous to orange brown caps and predominantly nondecurrent teeth - it would include Hydnum ''umbilicatum'', Hydnum oregonense, and Hydnum melitosarx, which are most reliably differentiated by spore size (in the absence of sequencing). |Niskanen(10) describe a taxon as Hydnum cf. umbilicatum because the type of Hydnum umbilicatum was not sequenced. Potential candidates for H. umbilicatum Peck (described from NY) currently known from eastern North America are H. canadense, H. mulsicolor, H. submulsicolor, H. quebecense, and H. cf. umbilicatum. The only one of these to produce at least some spores over 8.3 microns wide (as observed in the holotype) was H. cf. umbilicatum. "We therefore conclude that among the currently known eastern North American species, the one presented here [H. cf. umbilicatum] best fits the type material of H. umbilicatum" (Niskanen(10) with Latin name italicized). However, they include several clades in their phylogram ranging from eastern North America where the type was found to western North America and Eurasia. They comment that the infraspecific variation (>2%) is greater than in other Hydnum spp. but because the differences are not clear enough they treat H. cf. umbilicatum as one species. |Swenie(1) designated a neotype for Hydnum umbilicatum for which they give a distribution "Eastern North America - Michigan, Massachusetts, New York (type), Tennessee, North Carolina, Newfoundland and Labrador (GenBank KX388676), and Quebec (GenBank KX388675)." The correct name(s) for what has been called Hydnum umbilicatum in the Pacific Northwest might be Hydnum umbilicatum if we accept the Niskanen(10) decision to treat all of their Hydnum cf. umbilicatum as one species, including their western North American and Eurasian as well as eastern North American sequenced collections. The reason they gave for using ''cf.'' is that they had been unable to sequence the holotype. |In addition to the description derived from Niskanen(10) for Hydnum cf. umbilicatum, the Hall(1) and Castellano(2) descriptions for Hydnum umbilicatum are used for further detail even though their concepts would likely have included Hydnum oregonense as well (spore length given as 9.0-10 microns in both cases).

Odor:
none or fungoid (Hall)

Taste:
none (Hall)

Microscopic:
8.0-9.5 x 7.2-9.0 microns, average 8.7 x 8.1 microns, Q = 1.00-1.15, Q average = 1.08, [these measurements for western North American specimens: corresponding measurements for eastern North American specimens 8.4-9.6 x 7.8-8.8, 8.9 x 8.1, 1.07-1.13, 1.10 and for European specimens 7.8-9.2 x 7.4-8.8, 8.6 x 8.0, 1.00-1.16, 1.08], nearly round to somewhat elongated, thin-walled; an adjustment of the spore measurement by Huhtinen & Ruotsalainen (2006) of the holotype of H. umbilicatum Peck was 7.5-9.0 x 7.4-8.7 microns, average 8.4 x 8.0 microns, Q = 1.00-1.14, Q average = 1.06; basidia 2-spored or 3-spored, rarely 4-spored, 47-52 x 7.5-9.5 microns, sterigmata 4-7 microns long [these measurements for western North America specimens: in eastern North American specimens, basidia 2-spored or 3-spored, 47-55 x 9.0-11.5 microns, sterigmata 6.3-13.3 microns; in European specimens basidia 2-spored or 3-spored, 43-47 x 7.5-9.5 microns, sterigmata 4.5-6 microns long]; hyphae of the apex of the spines similar in western North American, eastern North American, and European specimens, cylindric, with cylindric to somewhat clavate ends 2.5-5 microns wide, hyphae yellowish, thin-walled, (Niskanen), spores 9.0-10.0 x 7.0-8.6 microns, nearly round, smooth, inamyloid; basidia 3-4-spored, 45-50 x 4.7-6.7 microns, clavate; cystidia absent; hyphae 2.7-4 microns wide, thin-walled, with abundant clamp connections, (Hall), 9.0-10.0 microns, "subglobose", smooth, inamyloid, (Castellano)

Spore Deposit:
white (Hall)

Notes:
The distribution of Hydnum cf. umbilicatum is circumboreal (Niskanen(10) who used specimens from BC, WA, NL, QC, TN, Germany, Finland, Slovenia, and China). Hydnum ''umbilicatum'' is found in WA, OR, CA, (Castellano), BC (collections at Pacific Forestry Centre and University of British Columbia), eastern North America and the Great Lakes area, (Phillips), NC (Coker), and NY (Peck''s holotype).