Russula olivacea
Description
Russula olivacea is an edible mushroom found mostly in groups from June in deciduous and coniferous forests, mainly under spruce and beech; not rare. The cap is convex when young, soon flat, yellowish-olive when young which develops into rusty brown; it ranges from 10–30 cm (3.9–11.8 in) in diameter. The gills are cream, deep ochre when old and rather crowded and brittle. The spores are yellow. The stem is strong and evenly thick, often pale pink. The flesh is firm, white, with a pleasant or innocuous scent, and has a mild or nutty taste.
Russula olivacea is one of several greenish Russulas that occur in California. These include Russula aeruginea, R. heterophylla, R. smithii, and R. urens.
Common names: Olive Russula.
Mushroom Identification
Cap
8.0-16.0 cm broad, convex, expanding to plano-convex or plano-depressed; margin decurved, then straight, not striate; surface glabrous, dry, dull-olive at the disc, lighter at the margin, background-color cream, sometimes showing through the primary olive pigment; in age, the cap often developing reddish, brownish or purplish areas, occasionally entirely reddish; context white, firm, unchanging, 1.0 cm thick at the disc; odor not distinctive; taste mild.
Gills
Adnate to adnexed, whitish and crowded when young, fairly well separated and cream-yellow in age, up to 1.0 cm broad, occasionally forked near the stipe; lamellulae absent.
Stipe
8.0-13.0 cm long, 2.0-3.5 cm thick, stuffed, more or less equal, the stipe base sometimes pointed; surface glabrous, slightly wrinkled to uneven, flushed pink over a pallid background, developing brownish discolorations where handled; context white, soft, unchanging when injured; partial veil absent.
Spores
8.5-10.5 x 7.5-9.0 µm, subglobose to obovoid, conspicuously warted, not reticulate, ornamentation amyloid.
Spore Print
Pale-yellow.
Habitat
Solitary or in small groups in mixed hardwood-conifer woods; fruiting from after the fall rains to mid-winter.
Look-Alikes
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Is distinguished by a greenish cap that does not become tinged reddish or brown with age, while Russula heterophylla and R. smithii can be separated by their white spore prints.
Russula urens
A smaller species can be differentiated by an acrid taste.
Russula viscida
In size and habitat very similar; the surface of its cap is bright purple to blood red and shiny. The base turns leather yellow when old. Its flesh is quite pungent.
History
The diminutive of red russa's diminutive is red, according to Russula's diminutive, which is red. The specific olivace epithet derives from olive: it is of olive-green, olive-orange color.
Photo sources:
Photo 1 - Author: Ryane Snow (snowman) (CC BY-SA 3.0)
Photo 2 - Author: Ron Pastorino (Ronpast) (CC BY-SA 3.0)
Photo 3 - Author: James Lindsey (CC BY-SA 2.5)