Hygrocybe acutoconica

Description

Hygrocybe acutoconica is a medium-sized waxy cap characterized by its pointed or conical cap, its yellow to orange colors, and the fact that it does not blacken with age or when bruised. Habitat on sandy soil or limestone-rich or chalky substrates.

Common names: Persistent Waxcap.

Mushroom Identification

1. Ecology

   Precise ecological role uncertain; growing alone or scattered under oaks and other hardwoods; late spring through fall (and overwinter in warmer climates); widely distributed in North America.

2. Cap

   1-4 cm; conical when young, becoming broadly conical, often with a central nipple; slimy or tacky; bald; yellow to orange; the margin often faintly lined, becoming uplifted and torn in age.

3. Gills

   Free from the stem or narrowly attached to it; close; thick; yellow to pale yellow or pale orange.

4. Stem

   2-6 cm long; 3-12 mm thick; equal, or tapered slightly to apex; dry; bald when young but soon fibrillose; often twisted; often becoming grooved or split lengthwise; pale yellow to orange, with a whitish base.

5. Flesh

   Yellowish; thin.

6. Odor and Taste

   Not distinctive.

7. Chemical Reactions

   KOH negative on cap surface.

8. Spore Print

   White.

9. Microscopic Features

   Spores 9-12 x 5-7 µ; smooth; ellipsoid; hyaline in KOH; inamyloid. Basidia is mostly 4-spored; to about 55 µ long. Hymenial cystidia absent. Lamellar trama parallel. Pileipellis an ixocutis.

Look-Alikes

1. Hygrocybe conica

   Similar in form and can occur with yellowish caps, but it blackens completely once the cap has expanded or if damaged by handling.

2. Hygrocybe conicoides

   Has yellow-orange gills and blackens slowly (and rarely all over); its cap is not markedly striate or radially fibrillose.

History

In 1893 American mycologist Frederick Edward Clements (1874 - 1945) gave this waxcap the scientific name Mycena acutoconica.

In 1949 it was moved to the genus Hygrocybe by German-born mycologist Rolf Singer, at which point its scientific name became Hygrocybe acutoconica. The basionym was for many years considered to be persistent, but Clements publication on this species predates others and so the accepted scientific name was changed recently to Hygrocybe acutoconica. You will still see the specific epithet persistent in many recently-published field guides, and indeed the common name Persistent Waxcap has been included in the British Mycological Society's list of Common Names of Fungi.

Hygrocybe acutoconica var. acutoconica has several synonyms including Mycena acutoconica Clem., Hygrophorus cuspidatus Peck, Bull., Hygrocybe constans J. E. Lange, Hygrocybe langei Kühner, Hygrophorus rickenii Maire, Bull., Hygrocybe persistens (Britzelm.) Singer, Hygrophorus langei (Kühner) A.H. Sm. & Hesler, Hygrocybe persistens var. langei (Kühner) Bon, and Hygrocybe aurantiolutescens P. D. Orton).

Hygrocybe acutoconica var. konradii (R. Haller Aar.) Boertm., has also acquired several synonymous scientific names among which are Hygrocybe konradii R. Haller Aar., Hygrophorus subglobisporus P. D. Orton, and Hygrocybe subglobispora (P. D. Orton) M.M. Moser.

Hygrocybe means 'watery head'. Much more obvious is the meaning of the specific epitet acutoconica, which refers to the acutely (sharply) conical form of caps of the Persistent Waxcap.

Photo sources:

Photo 1 - Author: Alan Rockefeller (CC BY-SA 4.0)

Photo 2 - Author: Missvain (CC BY-SA 4.0)

Photo 3 - Author: Eric Steinert (CC BY-SA 3.0)

Photo 4 - Author: Marjolein Tschur (CC BY-SA 4.0)