Lactarius deterrimus

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 cm (4.7 in) 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. Although the fungus is one of the most common in Central Europe, the species was not validly described until 1968 by German mycologist Frieder Gröger. Before this, L. deterrimus was regarded as a variety of L. deliciosus (L. deliciosus var. piceus, described by Miroslav Smotlacha in 1946). After Roger Heim and A. Leclair described L. semisanguifluus in 1950, this fungus was referred to as the latter. L. fennoscandicus was separated from L. deterrimus in 1998 by Annemieke T. Verbeken and Jan Vesterholt and was classified as a separate species. The epithet of deterrimus is Latin, and was chosen by Gröger to highlight the poor gustatory properties of the mushroom, such as the bitter aftertaste and often heavy maggot infestations. The superlative of 'dēterior' (meaning less good) means 'the worst, the poorest'. The mushroom is commonly known as the 'false saffron milkcap'. Several molecular phylogenetic analyses show that L. deterrimus, L. sanguifluus, Lactarius vinosus and L. fennoscandicus form a group of related species, which might include the North American species L. paradoxus and L. miniatosporus. Although L. deliciosus var. deterrimus qualifies as synonym for L. deterrimus, the families that had been characterized in North America as Lactarius deliciosus var. deterrimus are not closely related with the European types. They also seem not to form a monophyletic group. Lactarius deterrimus belongs to the section Deliciosi of the genus Lactarius. According to molecular phylogenetics studies, this section forms a definite phylogenetic group within the milk cap relatives. Deliciosi species mainly have an orange or reddish-coloured latex and taste mild to slightly bitter. They are strict mycorrhizal associates of conifers. The next closest relative of L. deterrimus is L. fennoscandicus. The cap is 3 to 10 centimetres (1.2 to 3.9 in), rarely up to 12 centimetres (4.7 in) wide and more or less centrifugal-shaped and round. It is at early stage convex and furled on the slightly churlish edge, and depressed in the centre and later flat, funnel-shaped depressed. The cap skin is bare, greasy in moist weather and slightly shiny when dry. The cap is tangerine to orange-brown, darker zoned towards the edges and dulls mainly yellow-brown. In old age or after cold or frost it changes the colour more or less to dirty greenish or green-spotted. The dense, bow-like lamellae are pale-orange to pale-ochre and on the stipe basifixed or slightly decurrent. They are brittle and intermixed with shorter lamellulae (short gills that do not extend fully from the cap margin to the stem) as well as partly forking near the stem. In old age or in cases of injury they receive initially dark red, later grey green spots. The spore print is pale ochre. The mainly long and cylindrical stipe is reddish orange. It is 4 to 8 centimetres (1.6 to 3.1 in) (rarely 10 centimetres (3.9 in)) long, 1 to 1.5 centimetres (0.4 to 0.6 in) wide and barely foveate or blotchy. On the basis it is often slightly thickened or pompous and becomes hollow inside. A bloomy circular zones is found on the lamella disposition.