Lactarius xanthogalactus

Lactarius xanthogalactus, commonly known as the yellow-staining milkcap is a poisonous species of fungus in the family Russulaceae. The species is found on the west coast of the United States and grows in the ground in association with hardwood and conifer trees. There are several other Lactarius species that bear resemblance to L. xanthogalactus, but most can be distinguished by differences in staining reactions, macroscopic characteristics, or habitat.

Lactarius xanthogalactus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Russulales
Family: Russulaceae
Genus: Lactarius
Species:
L. xanthogalactus
Binomial name
Lactarius xanthogalactus
Peck (1907)
Lactarius xanthogalactus
View the Mycomorphbox template that generates the following list
Gills on hymenium
Cap is depressed
Hymenium is decurrent
Stipe is bare
Spore print is white to yellow
Ecology is mycorrhizal
Edibility is unknown

Description

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The species produces mushrooms with pinkish-cinnamon caps measuring 3–11 cm (1.2–4.3 in) wide held by pinkish-white stems 2–6 cm (0.79–2.36 in) long and 1–2 cm wide.[1] When it is cut or injured, the mushroom oozes a white latex that rapidly turns bright sulfur-yellow. The spores are pale yellow, elliptical and bumpy.[1] It has an unpleasant taste.[1]

Taxonomy and classification

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The species was first described by American mycologist Charles Horton Peck in 1907.[2]

The specific epithet xanthogalactus is derived from the Greek words meaning "yellow" and "milk".

Similar species

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Lactarius chrysorrheus also produces yellow latex.

Lactarius vinaceorufescens has nearly identical microscopic features to L. xanthogalactus, but macroscopically it has reddish-vinaceous stains that develop on the cap, gills, and stem. Another lookalike is L. colorascens, but it may be distinguished from L. xanthogalactus by several features: a smaller fruit body; a whitish cap that becomes brownish-red with age and does not spot vinaceous or brown; bitter to faintly acrid latex; and slightly smaller spores. L. chrysorrheus is also similar, but it has a whitish to pale yellowish-cinnamon cap with slightly darker spots and grows under hardwoods (especially oak) on well-drained, often sandy soil, and its gills do not discolor or spot vinaceous or brown.[3]

Other superficially similar species include L. rubrilacteus, L. rufus, L. subviscidus, L. fragilis and L. rufulus, but none of these species have the yellow staining reaction characteristic of L. xanthogalactus.[4] It could also be mistaken with L. rubidus, which is redder and sweet smelling, and L. substriatus, which has a red-orange cap and white latex that yellows.[1]

Habitat and distribution

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The fruit bodies of Lactarius xanthogalactus grow scattered or in groups on the ground under conifers and hardwoods between August and January in Washington, Oregon and California.

See also

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References

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  1. ^ a b c d Davis, R. Michael; Sommer, Robert; Menge, John A. (2012). Field Guide to Mushrooms of Western North America. Berkeley: University of California Press. pp. 99–100. ISBN 978-0-520-95360-4. OCLC 797915861.
  2. ^ Peck CH. (1907). "New species of fungi". Bulletin of the Torrey Botanical Club. 34: 345–349.
  3. ^ Bessette AR, Bessette A, Harris DM (2009). Milk Mushrooms of North America: A Field Guide to the Genus Lactarius. Syracuse: Syracuse University Press. pp. 263–64. ISBN 0-8156-3229-0.
  4. ^ Arora D. (1986). Mushrooms Demystified: A Comprehensive Guide to the Fleshy Fungi. Berkeley, California: Ten Speed Press. p. 74. ISBN 0-89815-169-4.