Chlorophyllum olivieri

Appearance

Cap:
7-14(18)cm across, spherical when young, expanding to flat, not umbonate; "surface in the center smooth and dark red-brown, splitting up from the margin inward into concentric, brown, prostrate to erect, flat scales, the cream-colored trama somewhat showing through when young, +/- evenly gray- to olive-brown when old, margin obtuse, fibrillose-floccose", (Breitenbach), 5-15cm across, ovate then expanding to almost flat; "disrupting into broad, pallid, often slightly reflexed scales on fibrous background, giving the cap a shaggy, torn appearance", (Phillips), 5-12cm across, convex becoming flat with umbo when old; disc grayish olive brown, smooth, margin colored like disc but soon breaking up into coarsely fibrous scales on a dingy background, (Sieger), cap scales of similar color to background (often olivaceous brown, grayish brown), (Vellinga)
Flesh:
thick in center, thin toward margin; whitish, immediately turning orange-saffron-yellow when cut, then pink and finally red-brown, in stem discoloring like the cap flesh when cut, (Breitenbach), "white becoming orange to carmine red on cutting", (Phillips), cut flesh in stem staining reddish or saffron, (Sieger)
Gills:
free, 85-110 reach stem, broad, 3-7 subgills between each set of gills; white when young, then cream and spotting pink; edges "whitish when young, later brown-floccose", (Breitenbach), white, tinged reddish when older, bruising reddish, (Phillips), free, close, in two or three tiers; white becoming red or brown when bruised, darkening when old; edges finely fringed, (Sieger)
Stem:
9-16(18) x 1.2-1.6(2)cm, cylindric, "enlarged toward the base, base sometimes bent and bulbous to marginate-bulbous and white-tomentose, rigid, fragile, hollow, surface above the annulus whitish and smooth to longitudinally fibrillose, surface below it whitish and spotting red-brown to brown when touched, gray- to ocher-brown when old", (Breitenbach), 10-15cm x 1-1.5cm, widening toward the bulb which is usually oblique; "whitish tinged dirty pinkish-brown, bruising reddish brown when fresh", (Phillips), 7-15cm long, about 1 1/2 times as long as the diameter of the cap, 0.7-1.5cm wide, equal with abruptly bulbous base, stuffed; white, darkening when bruised, (Sieger)
Veil:
ring "membranous, cream-white, with a jagged margin, movable", (Breitenbach), double, membranous, movable on stem, (Phillips), thick, persistent, membranous, double ring, movable, white with lower surface darkening when old, edge fibrous and frayed, (Sieger)
Odor:
faintly like raw potatoes, (Breitenbach), strongly aromatic (Phillips), not remarkable (Sieger)
Taste:
mild, nutty, (Breitenbach), pleasant (Phillips), not remarkable (Sieger)
Microscopic spores:
spores (7.5)8.0-11.0 x 5.5-7.0 microns (average 8.7-10.0 x 5.8-6.6 microns) as compared to 8.8-12.7 x 5.4-7.9 microns (average 9.5-10.7 x 6.2-7.4 microns) for C. rachodes, (Vellinga), spores 8.8-11.2 x 6.8-8 microns, elliptic-oval, smooth, dextrinoid, colorless, thick-walled, with an indistinct germ pore; basidia 4-spored, 33-39 x 9-12 microns, clavate, with basal clamp connection; pleurocystidia not seen, cheilocystidia 21-47 x 12-20 microns, clavate to pyriform; septa without clamps in cap cuticle but clamps on many septa especially in hymenium, (Breitenbach), spores 10-12 x 6-7 microns, elliptic with germ pore, dextrinoid, (Phillips), spores 8-10.5 x 5-6.5 microns, oval, dark reddish brown in Melzer's (dextrinoid), with small germ pore; pleurocystidia absent, cheilocystidia clavate, not strangulated, (Sieger)
Spore deposit:
pale yellow (Breitenbach), white (Phillips)

Naming

Chlorophyllum rhacodes, C. olivieri and C. brunneum were formerly known as Macrolepiota rhacodes or Lepiota rhacodes, but the name was changed on the basis of molecular phylogenetic evidence demonstrating a closer relationship to Chlorophyllum molybdites than to Macrolepiota procera. The subspecies Macrolepiota rhacodes var. brunneum was also elevated to species status as Chlorophyllum brunneum. Chlorophyllum olivieri is a closely related species that is also eaten as the "Shaggy Parasol."
Many reference works spell the epithet "rachodes" rather than "rhacodes". The spelling "rachodes" was used by Vittadini when he first published the species in 1835, but was erroneous as the Greek word rhakos 'piece of cloth' should be transcribed as rhacos. However Index Fungorum keeps to the original author's spelling "rachodes" and so that is the form which should be regarded as correct.

Habitat

Single to gregarious "in coniferous forests, more rarely in hardwood forests, sometimes also in parks or gardens", summer to fall, (Breitenbach), "woods and shrubberies of all kinds, often with conifers"; summer to late fall, (Phillips), litter under hardwoods, (Sieger), from oak habitats in the Pacific Northwest, spruce and deciduous woods in Europe, (Vellinga)

Uses

The shaggy parasol is popularly praised as a choice edible mushroom. However, it contains toxins which can cause gastric upsets when eaten raw or undercooked, and some individuals show a strong allergic response even after cooking.

Furthermore, young shaggy parasols look identical to the poisonous Chlorophyllum molybdites (the mushroom that causes the most poisonings in North America yearly). Checking the spore print is essential as C. molybdites' print is green (older specimens have slightly green gills). As a result, this mushroom is not recommended for inexperienced hunters.

The shaggy parasol is similar in appearance to the similarly edible parasol mushroom, Macrolepiota procera. The latter grows considerably larger however, and is more likely to be found in the open than C. rhacodes which prefers more shade and dislikes open pastures and fields. Another distinguishing feature is that C. rhacodes lacks the brown bands that are on the stem of M. procera.