Russula grata

Description

Russula grata has a honey-brown to ochre cap with a deeply striate margin. Cap is slimy when wet and typically emerges with debris stuck to the cap. Gills cream, moderately close and brown with age; smells of bitter almonds or marzipan. Later smells foetid. Stains brownish. Grows from the ground in deciduous woods in summer and autumn. Extremely bitter taste.

Russula grata is an untidy mushroom, often damaged before it emerges from the forest floor.

Common names: Bitter Almond Brittlegill.

Mushroom Identification

1. Cap

   5 to 9 cm in diameter and more or less flat or slightly depressed in the center when fully developed, the caps are spherical only when very young.

   Honey brown and rather blotchy, the cap surface is viscid and develops intense radial ridges and warty bumps as it ages.

2. Gills

   The narrow, adnexed gills are moderately close together; they are very brittle. Initially, cream, the gills darken with age and develop rust spots.

3. Stem

   15 to 35mm in diameter and 4 to 8 cm tall, the brittle stems are white and solid, developing internal cavities as they age.

4. Spores

   Globose, 8-9.5 x 8-8.5 µm; uniquely ornamented with warts and protruding wings, sometimes branching; warts and ridges are up to 2 µm tall.

5. Spore Print

   Pale to mid cream.

6. Odor and Taste

   A strong odor of bitter almonds (some say rather like marzipan); the taste can be either mild or quite hot.

7. Habitat & Ecological Role

   Coniferous and broadleaf woodland. In common with other members of the Russulaceae, Russula grata is an ectomycorrhizal mushroom.

Look-Alikes

1. Russula fragrantissima

   Has much the same macroscopic appearance and strong almond fragrance but its spores do not have the distinctive wings associated with Russula grata.

2. Russula illota

   A rare species and considered by some authorities as a subspecies of Russula grata, is very similar in appearance, habitat, and season. Only experts can tell the two apart without resorting to microscopic examination.

3. Russula foetens

   Larger and has an unpleasant smell.

History

In 1893 German mycologist Max Britzelmayr (1939 - 1909) established its currently-accepted scientific name Russula grata.

Synonyms of Russula grata include Russula laurocerasi Melzer, and Russula subfoetens var. grata (Britzelm.) Romagn.

This brittlegill is included in many current field guides as Russula laurocerasi, the name given to it in 1921 by Czech mycologist Václav Melzer (1878 - 1968), the creator of Melzer's reagent which is used to stain certain parts of white fungi.

Russula, the generic name, means red or reddish, and indeed many of the brittlegills have red caps. The specific epithet grata means welcome.

Photo sources:

Photo 1 - Author: amadej trnkoczy (amadej) (CC BY-SA 3.0)

Photo 2 - Author: Richard Jacob (CC BY-SA 4.0)

Photo 3 - Author: amadej trnkoczy (amadej) (CC BY-SA 3.0)

Photo 4 - Author: amadej trnkoczy (amadej) (CC BY-SA 3.0)

Photo 5 - Author: Richard Jacob (CC BY-SA 4.0)