Boletus parasiticus Bull. ex Fr. syn. Xerocomus parasiticus (Fr.) Quél. Parasitenröhrling Cèpe parasite Cap 2–4cm, olivaceous straw-colour to sienna, slightly downy. Stem up to 40 x 10mm concolorous with cap often curved around or beneath host, tapering towards base. Flesh pale lemon-yellow, unchanging, flushed rust near stem base. Taste and smell not distinctive. Tubes lemon-yellow to ochraceous or even rust-coloured, adnate to subdecurrent. Pores lemon yellow becoming rust. Spore print olivaceous snuff-brown. Spores elongate, 11–21 x 3.5–5µ. Habitat unique, on Scleroderma citrinum, and therefore easily recognized. Season autumn. Rare. Said to be edible but not recommended.