Lactarius is a genus of mushroom-producing, ectomycorrhizal fungi, containing several edible species. The species of the genus, commonly known as milk-caps, are characterized by the milky fluid ("latex") they exude when cut or damaged. Like the closely related genus Russula, their flesh has a distinctive brittle consistency. It is a large genus with over 500 known species, mainly distributed in the Northern hemisphere. Recently, the genus Lactifluus has been separated from Lactarius based on molecular phylogenetic evidence.
Lactarius deterrimus, also known as false saffron milkcap or orange milkcap, is a species of fungus in the family Russulaceae. The fungus produces medium-sized fruit bodies (mushrooms) with orangish caps up to 12 centimetres wide that develop green spots in old age or if injured. Its orange-coloured latex stains maroon within 30 minutes. Lactarius deterrimus is a mycorrhizal fungus that associates with Norway spruce and bearberry. The species is distributed in Europe, but has also found in parts of Asia. A visually similar species in the United States and Mexico is not closely related to the European species. Fruit bodies appear between late June and November, usually in spruce forests. Although the fungus is edible—like all Lactarius mushrooms from the section Deliciosi—its taste is often bitter, and it is not highly valued. The fruit bodies are used as source of food for the larvae of several insect species. Lactarius deterrimus can be distinguished from similar Lactarius species by difference in the mycorrhizal host or latex colour.
Lactarius controversus, commonly known as the poplar milkcap, is a large funnel-capped fungus within the genus Lactarius, which are collectively known as 'milk caps'. They all exude milky drops (lactate) from the flesh and gills when damaged.
Lactarius torminosus, commonly known as the woolly milkcap or the bearded milkcap, is a large species of agaric fungus. A common and widely distributed species, it is found in North Africa, northern Asia, Europe, and North America. It was first described scientifically by Jacob Christian Schäffer in 1774 as an Agaricus, and later transferred to the genus Lactarius in 1821 by Samuel Frederick Gray. A variety, L. torminosus var. nordmanensis, is known from the United States, Canada, and Switzerland. L. torminosus officially became the type species of Lactarius in 2011 after molecular studies prompted the taxonomic reshuffling of species between several Russulaceae genera.
Tapinella atrotomentosa, commonly known as the velvet roll-rim or velvet-footed tap, is a species of fungus in the family Tapinellaceae. Although it has gills, it is a member of the pored mushroom order Boletales. August Batsch described the species in 1783. It has been recorded from Asia, Central America, Europe and North America. Tough and inedible, it grows on tree stumps of conifers. The mushroom contains several compounds that act as deterrents of feeding by insects.
Lactarius scrobiculatus, commonly known as the scrobiculate milk cap, is a basidiomycete fungus, belonging to the genus Lactarius, whose members are called "milk caps." Taxonomy places this species into subgenus Piperites, section Zonarii, subsection Scrobiculati. The distinctive fruiting bodies of this large fungus are locally common in forests throughout Europe and North America. It is regarded as inedible by some authors, but it is nevertheless eaten in parts of Europe.
Lactarius pyrogalus, commonly known as the fire-milk lactarius, is a species of inedible mushroom in genus Lactarius. It is greyish and differentiated from other grey Lactarius by its widely spaced, yellow gills. It is found on the forest floor in mixed woodland, especially at the base of hazel trees.
Lactifluus piperatus, commonly known as the blancaccio, is a basidiomycete fungus of the genus Lactifluus. It was the original type species of the genus Lactarius, before being moved to Lactifluus.
Lactarius blennius is a medium-sized mushroom of the genus Lactarius found commonly in beech forests in Europe, where it is mycorrhizal, favouring the European beech. It was first described by Elias Magnus Fries. Though its colour and size vary, it is distinctive because it is slimy when wet and exudes copious amounts of milk. It has been the subject of some chemical research, and it can be used to produce pigments and blennins. Blennins, some of which have shown potential medical application, are derived from lactarane, a chemical so named because of their association with Lactarius. The edibility of L. blennius is uncertain, with different mycologists suggesting that it is edible, inedible or even poisonous.
Lactarius glyciosmus, commonly known as the coconut scented milk cap, is a semi-edible mushroom in the genus Lactarius. It is typically coloured a greyish lilac, with the sometimes hollow stem a little lighter coloured than the cap. It has crowded, decurrent gills, and smells strongly of coconuts. Mycorrhizal, it can be found growing in soil at the base of birch trees in Europe.
Lactarius vietus is a species of fungus in the family Russulaceae, first described by Elias Magnus Fries. It produces moderately sized and brittle mushrooms, which grow on the forest floor or on rotting wood. The flattened-convex cap can vary in shape, sometimes forming the shape of a wide funnel. It is typically grey, but the colour varies. The species has crowded, light-coloured gills, which produce white milk. The spore print is typically whitish, but also varies considerably. The mushrooms typically have a strong, acrid taste and have been described as inedible, but other authors have described them as consumable after boiling. L. vietus feeds by forming an ectomycorrhizal relationship with surrounding trees, and it favours birch. It grows in autumn months and is fairly common in Europe, North America and eastern Asia.
Lactarius subflammeus, commonly known as the orange milk cap, is a species of fungus in the family Russulaceae. It is found in western North America in the late summer and fall and is especially common in the Pacific Northwest, where it grows on the ground near conifers like pine and spruce. The brightly colored fruit bodies, which are slimy or sticky, have scarlet caps when young that soon fade to brilliant orange. The stem—typically longer than the width of the cap—is also bright orange but the gills are whitish. The mushroom secretes a whitish latex when it is cut or injured.
Lactarius alnicola, commonly known as the golden milkcap, is a species of fungus in the family Russulaceae. The fruit bodies produced by the fungus are characterized by a sticky, vanilla-colored cap up to 20 cm (8 in) wide with a mixture of yellow tones arranged in faint concentric bands. The stem is up to 5 cm (2 in) long and has yellow-brown spots. When it is cut or injured, the mushroom oozes a white latex, which has an intensely peppery taste. The acrid taste of the fruit bodies renders them unpalatable. Two varieties have been named: var. pitkinensis, known from Colorado, and var. pungens, from Michigan.
Lactarius repraesentaneus, commonly known as the northern bearded milkcap, the northern milkcap, or the purple-staining bearded milkcap, is a species of fungus in the family Russulaceae. It has a northerly distribution, and is found in temperate regions of North America and Europe, associated with spruce trees. Distinguishing features of its fruit body include the large orange-yellow cap up to 18 cm (7.1 in) wide, cream to pale yellow gills, and a yellow coarsely-pitted stem that is up to 12 cm (4.7 in) long and 3 cm (1.2 in) thick. Cut fruit bodies ooze a white latex that will stain mushroom tissue lilac to purple. Several chemicals have been isolated and identified from the fruit bodies that can modify the growth of plants, and the mushroom also has antibiotic activity against Staphylococcus aureus. L. repraesentaneus is poisonous, and consumption causes stomach aches.
Lactarius fallax, commonly known as the velvety milk cap, is a species of fungus in the family Russulaceae. Found in both spruce and mixed conifer forests, it is a fairly common species in the Pacific Northwest region of North America, with a northerly range extending to Alaska. Its fruit bodies are medium-sized, with velvety, brown to blackish caps up to 2–9 cm (0.79–3.54 in) in diameter bearing a distinct pointed umbo. The caps are supported by velvety stems up to 8 cm (3.1 in) long and 1.5 cm (0.6 in) thick. The mushroom oozes a whitish latex when it is cut, and injured tissue eventually turns a dull reddish color. The eastern North American and European species Lactarius lignyotus is closely similar in appearance, but can be distinguished by its differing range.
Lactarius argillaceifolius is a species of fungus in the family Russulaceae. The mushrooms produced by the fungus have convex to flattened drab lilac-colored caps that are up to 18 cm (7.1 in) wide. The cream-colored gills are closely spaced together and extend slightly down the length of the stem, which is up to 9 cm (3.5 in) long by 3.5 cm (1.4 in) thick. The mushroom produces an off-white latex when injured that stains the mushroom tissue brownish.
Lactarius fuliginosus, commonly known as the sooty milkcap, is a species of fungus in the family Russulaceae. The medium-sized fruit bodies have velvety, grayish-brown caps and crowded gills. It is found in deciduous forests of Asia, Europe, and North America.
Lactarius scoticus is a member of the large milk-cap genus Lactarius in the order Russulales. It is found in Europe, where it grows in peat bogs in a mycorrhizal association with birch.
Lactarius torminosulus is a member of the large milk-cap genus Lactarius, in the order Russulales. A European species, it was officially described in 1996 from collections made in Norway. Fruit bodies (mushrooms) are small to medium-sized, yellowish orange in colour. Young specimens have a hairy cap margin; these hairs slough off in maturity—a field characteristic that can be used to help distinguish this species from the similar Lactarius torminosus. The fungus grows in a mycorrhizal association with dwarf birch species.
Necatorin is a highly mutagenic chemical compound with the molecular formula C15H8N2O3. It is found in some mushrooms including Lactarius necator, from which it was first isolated and characterized. It tests positive in the Ames test, an assay for mutagenicity. Crude extracts of L. necator are also highly mutagenic in a bacterial test system, and this effect it attributed to necatorin.
