1. Amanita onusta, ca. Roosevelt, Monomouth Co., New Jersey, U.S.A.
2. Amanita onusta, Tennessee, U.S.A.
3. Amanita onusta, Etra Lake Twp. Pk., East Windsor, Mercer County, New Jersey, U.S.A.
Amanita onusta usually has a rather small cap (13 - 76 mm wide), but its cap may be more than 100 mm wide on occasion. It is often densely covered by brownish gray volval warts.
The gills of this species are white at first and soon become yellowish and appear waterlogged.
Its stipe (rarely up to 150 × 15 mm including the basal bulb) is whitish and often decorated with brownish gray powdery. The partial veil is friable and soon lost. The bulb at the stipe base is narrow and root-like and sometimes strongly sinuous. Brownish gray volval warts are often densely placed at the top of the stipe's basal bulb. Sometimes, recurved scales with powdery universal veil on their tips replace the closely packed warts on the bulb in whole or in part.
The spores measure (7.0-) 8.0 - 11.0 (-13.0) × (5.0-) 5.5 - 7.0 (-8.3) µm and are broadly ellipsoid to ellipsoid to elongate (rarely subglobose or cylindric) and amyloid. Clamps are present at bases of basidia.
This species is often associated with oak or pine.
Another similar species is A.
atkinsoniana Coker. The latter has warts developing a distinct brownish to chestnut tint. On the cap of A. atkinsoniana, the
warts are significantly shorter (use 10x lens) than those of A.
onusta (Bas, 1969) and farther apart. On the bulb of A.
atkinsoniana, the warts appear in many parallel rows and don't
usually produce the recurved scales often seen on the upper bulb in A. onusta
Amanita onusta is a species of eastern North America; its range extends from Quebec south and west to at least Arkansas and Missouri (per Jay Justice). It infrequently occurs as far south as eastern Texas or the Gulf Coast states; David P. Lewis reports he has not seen it in this region since about 1982. The species can be very common locally, at least in the northeastern U.S.
"Deep south" collections of A. onusta (well photographed, well-documented, and well-dried) are solicited by RET.—R. E. Tulloss
The editors of this site owe a great debt to Dr. Cornelis Bas
whose famous cigar box files of Amanita nomenclatural information
gathered over three or more decades were made available to RET for computerization
and make up the lion's share of the nomenclatural information presented on this site.
The following text may make multiple use of each data field.
The field may contain magenta text presenting data from a type study
and/or revision of other original material cited in the protolog of the present taxon.
Macroscopic descriptions in magenta are a combination of data from the protolog and
additional observations made on the exiccata during revision of the cited original
The same field may also contain black text, which is data from a revision of the present
taxon (including non-type material and/or material not cited in the protolog).
Paragraphs of black text will be labeled if further subdivision of
this text is appropriate.
Olive text indicates a specimen that has not been
thoroughly examined (for example, for microscopic details) and marks other places in the text where data is missing or uncertain.
The following material (unless stated otherwise in the text) is based upon original research by R. E. Tulloss.
Bas (1969): Basidiome small to medium, rarely large.
Bas (1969): 25 - 100 (-150) mm wide, gray to pale gray to sordid whitish, convex to planar to concave, sometimes with low, broad umbo, dry to subviscid; context not described; margin nonsulcate, appendiculate; universal veil as conic to irregular warts, dark gray to to brownish gray to gray-brown, small to large, up to 4 mm high and 3 mm wide, firm to friable, diminishing in size toward margin, sometimes merely as floccose-granular layer at margin.
RET: 13 - 76 (-150) mm wide, pale gray, ??; context ??; margin ??; universal veil ??.
Bas (1969): free to narrowly adnate,, crowded to rather crowded, white to cream-yellow, up to 10 mm broad, ventricose, sometimes with dingy tinge, white minutely fimbriate or flocculose edge; lamellulae rounded-truncate to attenuate.
Bas (1969): 35 - 150 × 6 - 15 mm, equal or narrowing upward, solid, dark gray or brownish gray at base, paler upward, later pale gray to brownish gray or whitish, flocculose-fibrillose near apex; bulb subfusiform to ventricose-fusiform to nearly napiform, up to 40 mm wide, sometimes with tapering, root-like extension up to 60 mm long; context whitish to pale buff or gray; partial veil as floccose-felted remnants or (sometimes) as easily broken apical annulus, whitish to sordid cream; universal veil on lower stipe and upper portion of bulb as rather conspicuous warts or recurved scales, dark gray to brownish gray, in circles or scattered.
Bas (1969): Odor weak to strong and upleasant ("chloride of lime"). Taste weak.
Spot test for laccase (syringaldazine) - negative throughout basidiome. Spot test for tyrosinase (L-tyrosine) - positive throughout basidiome. Spot test for tyrosinase (paracresol) - positive in scattered spots in immature material, positive throughout basidiocme except for bulb of stipe in mature material. Voucher collections: Tulloss 8-23-85-E, 7-3-87-D.
Bas (1969): rather thick; filamentous hyphae 2 - 5 (-8) μm, interwoven, repent, sometimes refractive, gelatinizing with age.
RET: ?? µm thick, ??; filamentous, undifferentiated hyphae ?? µm wide,
forming open weave when viewed from above; vascular hyphae 3.3 - 17.8 µm wide,
branching, rather common, sinuous.
double click in markup mode to edit.
Bas (1969): bilateral; divergent elements subcylindric and up to 30 μm wide, some probably terminal.
RET: bilateral, divergent; subhymenial base including divergent inflated cells
up to 55 × 20 µm or larger; wcs = ?? µm; filamentous, undifferentiated hyphae ?? µm wide, ??; terminal, inflated cells, ??; vascular hyphae ?? µm wide, ??; clamps common, often larger than basidial clamps.
Bas (1969): ramose to subcellular, often with rather irregularly shaped cells.
RET: wst-near = ?? µm; wst-far = ?? µm;
ramose to inflated ramose to subcellular, 40 - 45 µm thick, comprising small inflated cells and uninflated or partially inflated short hyphal segments in branching structure, with basidia arising from cells of all types; clamps common to scattered, often larger than basidial clamps.
Bas (1969): 40 - 50 (-70) × 9 - 12 μm, mostly 4-, but some 2- or 3-sterigmate; clamps present.
RET: 46 - 57 × 10.2 - 11.9 µm, 4-sterigmate, with sterigmata up to ?? × ?? µm;
clamps and proliferated clamps common, small.
Bas (1969): On pileus: elements in rather long, parallel, erect rows; filamentous hyphae 3 - 8 μm wide, scattered, branching: inflated cells rather small, mainly ellipsoid, but also globose or ovoid or branched-inflated, gray-brown (intracellular pigment), 20 - 60 × 20 - 40 μm; vascular hyphae not abundant.
RET: On pileus: elements having subvertical orientation; filamentous, undifferentiated hyphae 1.9 - 5.7 µm wide,
branching, rather common in upper part of wart, plentiful near base of wart, ??; inflated cells grayish brown, subfusiform to
cylindric to clavate to ovoid to subglobose, up to 72 × 45 µm, becoming somewhat
gelatinized; vascular hyphae not observed. On stipe base: ??.
Bas (1969): longitudinally acrophysalidic; filamentous hyphae rather abundant; acrophysalides abundant; vascular hyphae occasional.
RET: longitudinally acrophysalidic; filamentous, undifferentiated
hyphae ?? µm wide, plentiful, branching, often constricted at septa; acrophysalides ??, up to 376 × 43 µm; vascular hyphae 7.0± µm wide, abundant locally, ??; clamps infrequent or absent(?).
Bas (1969): comprising ellipsoid to pyriform to clavate cells, up to 20 (-30) μm wide, sometimes in short chains.
from Bas (1969): [60/6/-] 8 - 11 × 5 - 8 µm, (Q = 1.2 - 2.0; Q = 1.3 - 1.7), colorless, hyaline, thin-walled, amyloid, broadly ellipsoid to ellipsoid to elongate, sometimes obovoid, sometimes slightly strangulate; apiculus not described; contents subgranular; color in deposit not reported.
composite of data from all material revised by RET: [215/12/12] (7.0-) 8.0 - 11.0 (-13.0) × (5.0-) 5.5 - 7.0 (-8.3) µm, (L = 8.3 - 10.5 (-11.0) µm; L’ = 9.4 µm; W = 5.7 - 6.5 (-7.1) µm; W’ = 6.1 µm; Q = (1.14-) 1.28 - 1.85 (-2.21); Q = 1.35 - 1.65 (-1.84); Q’ = 1.52), hyaline, colorless, smooth, thin-walled, amyloid, broadly ellipsoid to ellipsoid to elongate, rarely subglobose, rarely cylindric, ??; apiculus sublateral, cylindric; contents guttulate, ??; white in deposit.
Solitary to subgregarious. New Jersey: At 35 - 215 m elev. In deciduous forest with Acer rubrum, Fagus grandifolia, Prunus, Quercus, etc. New York: At 180 m elev. In sandy soil under Betula, Quercus, and Tsuga canadensis. Virginia: In mixed woods including Quercus, Acer, Pinus strobus, and Liriodendron tulipifera.
Bas (1969): U.S.A.: VERMONT: Windsor Co. - N. Pomfret, 18.viii.1881 A. P. Morgan s.n. (lectotype of Lepiota drymonia, plate only, IA).
NORTH CAROLINA—Watauga Co. - Blowing Rock, 17.viii.1922 W. C. Coker 5520 (NCU).
TENNESSEE— Unkn. Co. - GSMNP, 26.iv.1936 L. R. Hesler 9051 (TENN), 9.viii.1953 L. R. Hesler 20962 (TENN, 23.ix.1963 C. Bas 3908 (L).
U. S. A.:
CONNECTICUT—Litchfield Co. - Black Rock St. Pk., 10.viii.1983 D. C. & R. E. Tulloss 8-10-83-A (RET 104-8). Middlesex Co. - E. Haddam, Devil's Hopyard St. Pk. [41°28’32” N/ 72°20’25” W, 72 m], 4.ix.2011 Djerba Goldfinger & Kevin Scalzo s.n. [Tulloss 9-4-11-AA] (RET ).
MAINE—Cumberland Co. - unkn. loc., 16.ix.1984 S. S. Ristich s.n. [Tulloss 9-16-84-SSR-A] (RET 236-5). Sagadahoc Co. - Woolwich, 7.x.1995 S. S. Ristich s.n. (RET 159-7).
MASSACHUSETTS—Franklin Co. - Mt. Toby, 25.viii.1963 C. Bas 3798A (L). Hampden Co. - Springfield, Forest Park, 30.vii.1986 Ellen Greer s.n. [Tulloss 7-30-86-EG2] (RET 465-9).
NEW JERSEY—Mercer Co. - Hightstown [40°15’57” N/ 74°31’04” W], 22.vii.1981 R. E. Tulloss 7-22-81-B (RET 106-9); E. Windsor Twp., Etra Lk. Twp. Pk. [40°15’11” N/ 74°29’54” W], 3.vii.1987 M. A. King & R. E. Tulloss [Tulloss 7-3-87-D] (RET 087-8). Monmouth Co. - Upper Freehold Twp., Assunpink Wildlife Mgmt. Area, Roosevelt Rd. [40°12’41” N/ 74°28’38” W, 38 m], 21.vii.1981 R. E. Tulloss 7-21-81-E (RET 163-3), 4.viii.1981 R. E. Tulloss 8-4-81-A (RET 109-6), 18.ix.1981 M. A. King & R. E. Tulloss 9-18-81-E (RET 164-7), 11.vii.1982 D. C., M. H., & R. E. Tulloss 7-11-82-B (RET 340-10), 18.vii.1982 R. E. Tulloss 7-18-82-B (RET 472-7), -C (RET 472-2), -G (RET 472-6), 5.ix.1983 M. A. King, D. C. & R. E. Tulloss 9-5-83-B (RET 470-10), 23.viii.1985 R. E. Tulloss 8-23-85-E (RET ??), 8.ix.1999 R. E. & Mary Tulloss 9-8-99-K (RET 297-3). Morris Co. - Mendham, Meadowood Twp. Pk. [40°47'31" N/ 74°38'43" W, 214 m], 27.vii.1986 S. Hopkins et al. s.n. [Tulloss 7-27-86-E] (RET ??); Morristown, 27.viii.1981 Al Northrup s.n. [Tulloss 8-27-81-AN] (RET 166-10); Schiff Nature Preserve, Mendham [40.75003° N/ 74.62975° W, ca. 105 m], 2.ix.2012 NJMA foray participant s.n. (RET 583-8).
NEW YORK: Ulster Co. - Mt. Tremper, jct. Esopus Crk. & Ashokan Reservoir, "Chimney Hole," right bank [41°59'31" N/ 74°16'14" W, 180 m], 15.ix.2009 Wm. Bakaitis s.n. (RET 479-7).
NORTH CAROLINA—Macon Co. - Highlands, vii.2008 Debbie Viess s.n. (RET 445-8).
PENNSYLVANIA—Luzerne Co. - unkn. loc., 21.viii.2011 D. Wasilewski s.n.[mushroomobserver.org 74498] (RET 499-6).
TENNESSEE—Blount Co. - GSMNP, Turkey Pen Ridge Tr. trailhead at Laurel Crk. Rd., 2.vii.2006 Maj Padamsee [TFB 13128] (TENN ??).
VIRGINIA—Franklin Co. - ca. Ferrum, ca. Ferrum College, 4.viii.1982 Gerald Bills, Pierre Dery, O. K. & H. H. Miller OKM19946 (VPI, as "A. peckiana").
WEST VIRGINIA—Marion Co. - Mill Fall Run, 21.ix.1992 R. P. Bhatt A2 (FWVA).
Bas (1969): "Nomenclatural note.—It was not without hesitation that I decided to apply the name Agaricus onustus Howe to the present species. In the protologue of the name a few aberrant characters are mentioned; unfortunately I have been unable to trace the type.
"Agaricus onustus is described by Howe as having a brownish gray cap with a nonsulcate margin, dust coloured warts leaving dark spots when rubbedoff, and a white farinose, very glutinous, ringless stem with a large, rooting, concentrically squamulose bulb.
"This description applied fairly well to the present species, except for the gultinous stem, which is a very unusual feature for any species of Amanita. It is remarkablethat the stem is at the same time said to be farinose. I am of the opinion that these two seemingly contradictory characters refer to the subfloccose remnants of the creamy to friable ring, which in the present species sometimes covers the whole stem and sticks to the fingers when touched. This interpretation was given by Morgan (1887: 32) in his description of Agaricus onustus.
"I must mention that Howe described cap as being 5 - 6 inches (about 12.5 - 15.5 cm) wide, which is considerably wider than in any of the specimens I examined. Now and then, however extraordinar[il]y large specimens of nearly all species of agarics are found.
"In applying Howe's name to the species described above, I am following Morgan (1887: 32) and Peck (1900: 826, 839; two collections in NYS). After the publication of Amanita cinereoconia by Atkinson in 1909, this [latter] name has frequently been misapplied to the present species. [See Bas' comments on A. cinereoconia.]
"Coker (1917: 49) considered Agaricus onustus Howe to be a synonym of Amanita muscaria.... In my opinion this view is difficult to defend because of the smooth margin and the colour of the cap. Also in North American forms of A. muscaria the margin is somewhat sulcate in well-expanded caps."
The unpublished coloured type plate of Lepiota drymoniaMorgan is an artistic drawing of onelarge fruit-body of a species of Amanita with an appendiculate margin of the cap and lilaceous grey-brown, more or less pyramidal to recurving scale-like warts on the cap and on the ventricose-fusiform bulbous base of the stem. It has a ragged apical ring and a squamulose lower half of the stem. The type specimen has not been preserved by Morgan. In the published description the colour of the volva is described as drab to pale umber. I am convinced that Morgan's plate represents a luxuriant specimen of the species described above.
"Amanita onusta is not especially rare in the eastern and north-eastern U.S.A. It is a very characteristic species because of the crowded, more or less conical, grey warts on the cap and similar or paler warts or recurving scales at the base of the stem. It often occurs in a rather small, slender form with a slender, deeply rooting base, and conspicuous, carrow, recurving scales at the lower part of the stem and upper part of the rooting base.
"Amanita onusta is often incorrectly called A. cinereoconia.... However that species is easy to distinguish by the absence of clamps, its usually somewhat more slender spores, its powdery-flocculose to powdery-verrucose cap, and the absence of true warts or scales at the base of the stem.
Each spore data set is intended to comprise a set of measurements from a single specimen made by a single observer;
and explanations prepared for this site talk about specimen-observer pairs associated with each data set.
Combining more data into a single data set is non-optimal because it obscures observer differences
(which may be valuable for instructional purposes, for example) and may obscure instances in which
a single collection inadvertently contains a mixture of taxa.