Ruby Butter (Rubinoboletus rubinus)
- Division: Basidiomycota (Basidiomycetes)
- Subdivision: Agaricomycotina (Agaricomycetes)
- Class: Agaricomycetes (Agaricomycetes)
- Subclass: Agaricomycetidae (Agaricomycetes)
- Order: Boletales (Boletales)
- Family: Boletaceae (Boletaceae)
- Genus: Rubinoboletus (Rubinobolet)
- Type: Rubinoboletus rubinus (Ruby butterdish)
- Pepper mushroom ruby;
- Rubinobolt ruby;
- Chalciporus ruby;
- Red mushroom;
- Xerocomus ruby;
- A red pig.
head reaching 8 cm in diameter, at first hemispherical, eventually opening up to convex and almost flat, painted in brick-red or yellow-brown tones. The hymenophore is tubular, the pores and tubules are pinkish-red, not changing color when damaged.
Leg central, cylindrical or club-shaped, usually tapering downwards. The surface of the leg is pinkish, covered with a reddish coating.
Pulp yellowish, bright yellow at the base of the stem, does not change color in the air, without much taste and smell.
Споры broadly elliptical, 5,5–8,5 × 4–5,5 µm.
Distribution – It grows in oak forests, is very rare. Known in Europe.
Edibility – An edible mushroom of the second category.