Boletus luridiformis Rostk. syn. B. erythropus sensu auct. mult. (illustrated 45% life size) Cap 8–20cm across; bay to walnut-brown with olivaceous tints, tending to yellowish-ochre towards the margin, bruising blue-black; slightly velvety at first, soon becoming smooth, sometimes slightly viscid when wet. Stem 45–145×20–50mm; yellowish, densely covered in red dots; robust. Flesh yellow, immediately dark blue on cutting; taste and smell not distinctive. Tubes lemon-yellow then greenish, turning dark blue on cutting. Pores small, round; orange-red, becoming rusty with age, readily bruising dark blue to black. Spores 12–15×4–6¼, subfusiform. Spore print olivaceous walnut-brown. Habitat in coniferous, broad-leaved, and mixed woodland; late summer to autumn. Frequent. Edible only when cooked, can cause gastric upsets. Note this dramatically coloured fungus was previously named B. erythropus and commonly reported.