Gyrodon lividus
Description
Gyrodon lividus is an edible pored mushroom bearing close affinity to the genus Paxillus. Fruit bodies are distinguished from other boletes by decurrent bright yellow pores that turn blue-gray on bruising. Widespread in Europe, but rare in some countries.
Fruit bodies of Gyrodon lividus contain the cyclopentanedione compounds chamonixin and involution.
Common names: Alder Bolete.
Mushroom Identification
Cap
Up to 7 cm, at first hemispherical then expanding to convex or flat-convex, whitish, cream, pale ochraceous, pale buff to buff, pale yellowish brown, pale cinnamon, sometimes almost grey, often with reddish tints, sometimes rusty-spotted, viscid especially in wet weather, otherwise dry, smooth or felty, sometimes scaly.
Stipe
Often eccentrically attached, cylindrical or spindle-shaped, and usually tapering towards the base, mostly cream or yellow, often in places with rusty to brownish tinges.
Flesh
Cream in the cap, yellowish to orange-yellow in the stipe, usually brownish in the stipe base, blueing in the cap, and unchanging in the stipe when exposed to air.
Tubes
Very short, not exceeding 5 mm, yellow to bright yellow when young, later with some olivaceous tint, decurrent (going down the stipe), blueing when exposed to air.
Pores
Yellow to bright yellow when young, later with some olivaceous tint, blueing when bruised.
Odor and Taste
Smell not distinctive. Taste is not distinctive.
Spores
5–8 × 3.5–4.5 μm. The spore print is olive-brown.
Habitat
In a variety of habitats, where its mycorrhizal trees, alders (Alnus), are present.
Similar Species
Boletinellus merulioides, which is generally a larger mushroom overall with larger spores and grows under ash (Fraxinus), or B. proximus, a dark brown or purple-brown capped species that does not change color when bruised and is found only in Florida.
History
The alder bolete was initially described by French mycologist Pierre Bulliard in 1791 as Boletus lividus, before being given its current binomial name in 1888 by Pier Andrea Saccardo when he transferred it to Gyrodon. When Saccardo circumscribed Gyroporus, he included Boletus sistotremoides (published by Elias Fries in 1815) as the type species.
Rolf Singer later determined that Fries's taxon was the same species as Gyroporus lividus. Before this, in 1886 Lucien Quélet erected the genus Uliporus with Boletus lividus as the type. As a result of Singer's discovery, the genus Uliporus was rendered obsolete, and Boletus sistrotremoides became synonymous with Gyropus lividus.
The generic term Gyrodon is derived from the Ancient Greek gyros "whorl" and odon "tooth", while the specific epithet lividus is Latin for "lead-colored". The fungus is commonly known as the alder bolete.
Molecular research confirms the relations of the genus Gyrodon and the gilled genus Paxillus as sister taxa, and one of the earliest diverging lineages of the suborder Boletineae.
Photo sources:
Photo 1 - Author: Urmas Ojango (Attribution-NonCommercial 2.0 Generic)
Photo 2 - Author: Urmas Ojango (Attribution-NonCommercial 2.0 Generic)
