|Major Groups > Gilled Mushrooms > Pale-Spored > Lactarius > Lactarius imperceptus|
by Michael Kuo
Found under oaks in eastern North America, Lactarius imperceptus is a brownish species with white milk that turns yellow when exposed to air . . . in theory. In practice the cap is sometimes rather pinkish, and the yellowing of the milk may be faint (even absent) and/or slow to develop. The cap is never zoned, helping to separate it from other oak-loving species with yellowing milk, like Lactarius chrysorrheus.
Ecology: Mycorrhizal with oaks (especially southern live oaks) and possibly with other hardwoods; summer and fall; widely distributed east of the Great Plains.
Cap: 2.5-9 cm; convex, with an incurved margin when young, becoming flat or shallowly depressed, often with a central bump; dry or moist; bald; dull brown to tan, cinnamon tan, pinkish brown, or paler; consistently without zones of color or texture.
Gills: Attached to the stem or beginning to run down it; close; whitish to pinkish or very pale tan; often developing cinnamon to reddish brown stains and discolorations.
Stem: 2.5-9 cm long; up to about 1.5 cm thick; more or less equal; dry or moist; without potholes; smooth; pale at first, becoming colored like the cap.
Flesh: Thin; pale, becoming pinkish; not changing when sliced, or turning slowly yellowish to yellow.
Milk: Creamy; turning slightly to substantially yellowish (often very slowly) or not yellowing appreciably; not staining tissues, or staining them yellowish; staining white paper yellow.
Odor and Taste: Odor not distinctive; taste usually acrid but sometimes weakly so.
Spore Print: White to yellowish.
Microscopic Features: Spores 7-9.5 x 6-8 µ; broadly ellipsoid; ornamentation 0.5-1.5 µ high, as amyloid warts and ridges that form broken reticula or remain scattered. Pleuromacrocystidia to about 70 x 10 µ; fusiform to fusoid-mucronate or subcylindric, often with an apical constriction. Cheilomacrocystidia similar but shorter. Pileipellis an ixolattice or ixotrichoderm, with the gelatinous material quickly dissolving in KOH mounts.
Further Online Information:
Cite this page as:
Kuo, M. (2011, March). Lactarius imperceptus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/lactarius_imperceptus.html