Hygrocybe intermedia

What You Should Know

Hygrocybe intermedia belongs to the European waxcap assemblage whose members are globally red-listed based on the declining area/quality of their grassland habitat. They are rapidly disappearing across Europe due to changes in land use (agricultural intensification and decline of traditional farming practices) and increasing use of fertilizers and pesticides.

It has a conical then expanding cap that sometimes is lobed. Surface dry and fibrous, center scurfy, red then orange or orange-yellow, to about 6 cm across. Gills are only partly attached or free, whitish to pale yellow, thick, edge sometimes serrated.

Other names: Fibrous Waxcap.

Hygrocybe intermedia Mushroom Identification

1. Cap

   3 to 9 cm in diameter, the cap is broadly conical at first, becoming convex and eventually almost flat, sometimes splitting at the margin. Initially, the cap color is reddish, becoming orange-yellow with a paler margin at maturity. The cap surface is dry and scurfy with radial fibrils. Flesh yellowish.

2. Gills

   Adnexed or free, thick, moderately spaced, whitish to pale yellow sometimes with an orange tinge; gill edges often serrated.

3. Stem

   Orange-yellow on the surface and streaked with reddish longitudinal fibers. Dry, cylindrical, and hollow, with no stem ring; 0.5 to 2cm in diameter and 3 to 9 cm tall.

4. Gill Trama

   Regular, with hyphal elements 200 - 700μm long x 9 - 15μm in diameter.

5. Spores

   Ovoid, pyriform (pear-shaped) or broadly ellipsoidal, 8-11 x 5-6.5μm; inamyloid.

6. Spore Print

   White.

7. Pileipellis

   A slightly differentiated cutis with surface squamules comprising fascicules of erect hyphal cells with tapering terminal hyphal elements 80 - 240 long x 10 - 30μm diameter.

8. Odor and Taste

   Not distinctive.

9. Habitat & Ecological Role

   In unimproved grassland on alkaline to mildly acidic soils.

Hygrocybe intermedia Look-Alikes

1. Hygrocybe chlorophana

   Has a smooth cap that is slimy in wet weather.

2. Hygrocybe reidii

   Has a smooth cap; its crushed gills smell like honey.

3. Hygrocybe acutoconica

   Usually more yellow and has a smooth cap surface but a fibrous stem; its spores are more cylindrical (Q value 1.9 compared with typically 1.6 for Hygrocybe intermedia.)

Hygrocybe intermedia Taxonomy and Etymology

Originally described in 1872 by Italian botanist Giovani Passerini (1816 - 1893), who named it Hygrophorus intermedius, the Fibrous Waxcap was relocated to its present genus in 1889 by Swiss mycologist Victor Fayod (1860 - 1900), thereby establishing its currently-accepted scientific name as Hygrocybe intermedia.

The genus Hygrocybe is so named because fungi in this group are always very moist. Hygrocybe means 'watery head'. The specific epithet intermedia comes from the Latin inter and media which translates to 'in the middle'.

Synonyms: Godfrinia intermedia (Pass.) Herink, Pseudohygrocybe intermedia (Pass.) Kovalenko, Mikol.

Sources:

Photo 1 - Author: Lukas from London, England (Creative Commons Attribution-Share Alike 2.0 Generic)

Photo 2 - Author: Lukas from London, England (Creative Commons Attribution-Share Alike 2.0 Generic)

Photo 3 - Author: Per Fadnes (Creative Commons Attribution 4.0 International)