Ruby Butyrum (Rubinoboletus rubinus)
- Division: Basidiomycota (Basidiomycetes)
- Subdivision: Agaricomycotina (Agaricomycetes)
- Classis: Agaricomycetes (Agaricomycetes)
- Subclass: Agaricomycetidae (Agaricomycetes)
- Order: Boletales (Boletales)
- Genus: Boletaceae (Boletaceae)
- Genus: Rubinoboletus (Rubinobolet)
- Type: Rubinoboletus rubinus (Ruby butterdish)
- Piper fungus rubinus;
- Rubinobolt ruby;
- Chalciporus rubinus;
- Fungus ruber;
- Xerocomus rubinus;
- Porcus ruber.
caput 8 cm diametro attingens, primo hemisphaerico, demum patens usque ad convexa et fere plana, tonis lateritio-rubris vel flavo-brunneis depictis. Hymenophora est tubulosa, poris et tubuli reniformi-rubescentes, non mutato colore laesi.
crus centralis, cylindraceus vel clavatus, plerumque deorsum attenuatus. Superficies cruris reniformi est, vestitu rubente obsita.
pulpam flavescens, flavescens, ad basin caulis, colorem in aere non mutat, absque multo sapore et odore.
quaestiones late elliptica, 5,5–8,5 4-5,5 µm.
distributio — Nascitur in silvis quercu rarissima. Notus in Europa.
Edibility — Fungus eduli secundi generis.