Leucocoprinus leucothites
Index Fungorum 551: 1. 2023.
Common Name: none
Synonyms: Leucoagaricus leucothites (Vittad.) Wasser; Leucoagaricus naucinus (Fries) Singer; Lepiota naucina (Fries) P. Kummer
Cap 4.0-9.0 cm broad, hemispherical, becoming convex, plano-convex in age; margin incurved, then decurved, sometimes appendiculate from veil fragments; surface glabrous to appressed-squamulose in dry weather, less commonly radially cracked; color dull-white to buff, occasionally tinged grey, the disc darker; flesh white, soft, thick, unchanging when cut; odor and taste mild.
Gills free, close, broad, white, unchanging when bruised, aging pinkish to pinkish-tan.
Stipe 5.0-11.0 cm tall, 0.7-1.4 cm thick, round, brittle, stuffed at maturity, enlarged to sub-bulbous at the base; surface smooth to silky, pallid, bruising yellowish to brownish; veil membranous forming a persistent, thick, double-edged, moveable, superior annulus.
Spores 6.5-8 x 4.5-5.5 µm, broadly elliptical, smooth, thin-walled, dextrinoid, with an apical pore; spore print white to pale-pinkish.
Solitary, scattered, to gregarious in grassy areas, parks, gardens, and woods; fruiting from late summer to early winter; common.
Edible, but caution is advised because of possible confusion with poisonous Amanitas. Some allergic reactions have also been reported.
Traditionally known as Leucoagaricus naucinus, most mycologists now regard this name as a synonym of Leucoagaricus leucothites/Leucocoprinus leucothites, which has nomenclatural priority. Fieldmarks include a whitish, glabrous cap, sometimes tinged buff to pale-grey, gills that are tinged pinkish at maturity, and a sub-bulbous stipe that bruises yellowish to brown on handling. Beginning mycophagists should avoid this species because of its resemblance to deadly white Amanitas. In our area this would include the white form of Amanita phalloides as well as Amanita ocreata. These two Amanitas can be distinguished by the presence of a sac-like volva and a membranous, fixed ring. Two other mushrooms occasionally confused with Leucoagaricus naucinus are Volvariella speciosa and Agaricus campestris. Volvariella speciosa typically fruits in disturbed habitats, e.g. iceplant, agricultural fields etc. It has pinkish, free gills, but has a volva and lacks a veil. Agaricus campestris has pinkish, free gills which become blackish-brown at maturity. Additionally it has a poorly developed, evanescent ring.
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Smith, A.H. (1949). Mushrooms in their Natural Habitats. Sawyer's Inc: Portland, OR. 626 p. (PDF)
