Boletus luridus, known as the lurid bolete, is a fungus of the bolete family, found in deciduous woodlands in Europe and eastern North America. Fruiting bodies arise in summer and autumn and may be common. It is a solid bolete with an olive-brown cap, orange pores and stout ochre stem patterned with a reddish meshwork. Like several other red-pored boletes, it stains blue when bruised or cut. Though edible when cooked, it can cause gastric upset when raw and be confused with the poisonous Boletus satanas, though this has a pale cap.
Taxonomy
Boletus luridus was described by Jacob Christian Schaeffer in 1774 and still bears its original name. Its specific epithet is the Latin adjective luridus, 'sallow'. The American common name is lurid bolete. Both it and Boletus satanas are known as ayimantari 'bear mushroom' in Eastern Turkey.
Description
B.luridus is a stout fungus with a yellow-olive to olive-brown convex cushion-shaped cap that can reach  in diameter. The cap surface is tomentose (velvety), becoming smoother with old age, and sticky in wet weather. It has free orange or yellowish pores and yellow tubes underneath. The thick stem is colored with a red meshlike pattern on a paler ochre background. The flesh is yellowish, with red marks in the cap, and stains dark blue when bruised or broken. There is a faint sour smell and the taste is described as mild. The spore dust is olive coloured. The mycelium is an unusual yellow colour.
B. satanas is larger, has a pale cap and a putrid smell at times.

Distribution and habitat
The fungus grows in association with deciduous trees such as oak, birch and beech on calcareous (chalky) soils, from June to November after summer rains. It may occur in parks near a single tree, though it will not be found in acidic soils. It is widespread in Europe, east to the Black Sea region and eastern Anatolia in Turkey, as well as in the Eastern United States and Canada. It has been recorded from La Malinche National Park in Mexico, and once from Costa Rica.
Toxicity
Mild tasting, Boletus luridus is edible after thorough cooking and has been reported as popular in France. However, caution is advised as it resembles other less edible blue-staining boletes and should be avoided by novice mushroom hunters. It can cause nausea and vomiting if eaten raw or insufficiently cooked, or with alcohol. It is not considered edible in Mexico.
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