Hydnellum spongiosipes

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by Michael Kuo

If you have ever seen an old tree that has "swallowed" a length of barbed wire or an old road sign, you've seen the slow-motion version of what species of Hydnellum often manage to do in a few short days of growth. Like other Hydnellum species, Hydnellum spongiosipes frequently engulfs its surroundings as it develops, and a typical specimen--in my experience, anyway--has swallowed at least one or two oak leaves.

Distinguishing features for Hydnellum spongiosipes include the brownish "teeth" on the underside of the cap, which bruise darker brown; the brown, velvety cap surface; the "duplex" flesh (with a soft, spongy layer and a harder, dark layer beneath it); the convex cap that becomes flat with age but not, typically, depressed or vase-shaped; and the spongy, swollen stem that gives the species its Latin name. Hydnellum spongiosipes grows under oaks east of the Rocky Mountains.

Description:

Ecology: Mycorrhizal with oaks (especially white oak) and other hardwoods; growing alone or gregariously; summer and fall; widely distributed east of the Rocky Mountains.

Cap: Single or fused with other caps; 2-10 cm wide; convex, becoming broadly convex to flat; cinnamon brown to dark brown; velvety; sometimes rugged or pitted; paler areas bruising dark brown.

Undersurface: Running down the stem; covered with crowded spines that are 4-7 mm long; pale to lilac brown; sometimes bruising dark brown; darker brown in age.

Stem: 3-10 cm long; 1-3 cm thick at apex; club-shaped; swollen and much thicker below; spongy; dark brown; velvety.

Flesh: Upper layer pale brown and fairly soft; lower layer dark brown to purplish brown and corky.

Odor and Taste: Odor mealy or not distinctive; taste mealy or mild.

Chemical Reactions: KOH on flesh olive green to blackish or slowly black.

Spore Print: Brown.

Microscopic Features: Spores 4.5-7 x 4-5.5 µ; subglobose or irregular; prominently tuberculate. Clamp connections absent.

REFERENCES: (Peck, 1897) Pouzar, 1960. (Saccardo, 1899; Coker & Beers, 1951; Smith, Smith & Weber, 1981; Baird, 1986; Baird & Kahn, 1986; Lincoff, 1992; Barron, 1999.) Herb. Kuo 06249605, 07170405.

Hydnellum velutinum, in the sense of some North American authors (e.g. Coker & Beers, 1951), is a synonym.

Further Online Information:

Hydnellum spongiosipes at Roger's Mushrooms

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Cite this page as:

Kuo, M. (2009, April). Hydnellum spongiosipes. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/hydnellum_spongiosipes.html