Russula ochroleuca

Description

Russula ochroleuca is a member of the genus Russula. A group that has become known as brittlegills. It is found in all kinds of woodland from mid-summer through to early winter. It is edible, but the taste is mediocre and sometimes rather peppery and so this abundant mushroom is not much prized for its culinary value.

The cap is dull yellow and 5–12 cm (2–4.5 in) wide, initially convex, later flat, or slightly depressed. The cap margin becomes furrowed when mature, and it is two-thirds peeling. The gills are white to grayish white and are adnexed. The stipe is 3–7 cm (1–3 in) long, 1–2 cm (0.5–1 in) wide, cylindrical, white, or later grayish.

In the USA it is fairly common under conifers; birch, and aspen in the Northern States.

Common names: Ochre Brittlegill, Common Yellow Brittlegill.

Mushroom Identification

1. Cap

   5 to 12 cm in diameter, the ochre-yellow cap is initially convex and then flat, developing a slight depression at maturity.

   As the fruitbodies age, the cap margin becomes striate and the cuticle easily peels back over the outer two-thirds of the diameter. Most specimens remain yellow, but a few develop a green tinge to the cap.

   Beneath the surface, the flesh of the Ochre Brittlegill is white and brittle.

2. Gills

   The creamy-white gills of Russula ochroleuca are adnexed or adnate, narrow and brittle; they gradually turn a darker shade of cream as the fruiting body matures.

3. Stem

   15 to 25mm in diameter, the stems are 4 to 7cm tall, white at first but greying slightly with age. The stem usually tapers inwards slightly towards the apex.

4. Spores

   Broadly ellipsoidal to ovoid, 8-10 x 7-8µm; ornamented with warts up to 1.2µm tall connected with very fine lines to form an almost complete network.

5. Spore print

   Pale cream.

6. Odor and Taste

   No distinctive odor; taste variable from mild to fairly hot.

7. Similar species

   Russula claroflava is found on the wet ground under birch trees. It has a strong fruity odor, has yellowish gills and provides a yellow-ochre spore print.

History

This brittlegill was described scientifically in 1796 by Christiaan Hendrik Persoon, who gave it the binomial name Russula ochroleuca by which it is generally known today.

Synonyms of Russula ochroleuca include Agaricus ochroleucus (Pers.) Fr., Russula citrina Gillet, Russula granulosa Cooke, and Russula ochroleuca var. granulosa (Cooke) Rea.

Russula, the generic name, means red or reddish, and indeed many of the brittlegills have red caps. The specific epithet ochroleuca is made up of the prefix ochr- which means ochre (brownish yellow). and -leuca meaning white; so ochroleuca means whitish (light) ochre - the typical cap color.

Photo sources:

Photo 1 - Author: Holger Krisp (CC BY 3.0)

Photo 2 - Author: Atheox (CC BY-SA 3.0, 2.5 Generic, 2.0 Generic and 1.0 Generic)

Photo 3 - Author: Holger Krisp (CC BY 3.0)

Photo 4 - Author: Leonhard Lenz (CC BY-SA 4.0)