1. Amanita aestivalis, south central, New York [state], U.S.A.
The following is based in large part on the original
description by Singer (1959b).
The entire fruiting body of A. aestivalis, slowly stains some shade of
red-brown to brown (because of bruising, cutting, age, etc.).
The cap is 54 - 83 mm
wide, entirely white with the occasional exception of
pale tan or pale yellow over the center, and ranges from
parabolic-obtuse at first to convex to planar as it
matures. The margin is nonstriate or very short striate
and not appendiculate; sometimes it flares upward in age.
The volva is usually absent from the cap, but sometimes
may be present at first in thin, submembranous patches.
The gills are free, close,
white, subventricose, moderately broad, and with slightly
fimbriate edges. Form of short gills was not originally
The stipe 90 - 160 × 6 - 16 mm, white, cylindric or narrowing upward, usually
without notable decoration, and stuffed. The stipe bears
a white, superior, persistent annulus. There is a broad
(up to 33 mm or more wide), rather abrupt, vertically
cleft bulb at the stipe's base. This bulb is sometimes
marginate (with a fragile, thin, raised rim 1- 10 mm high
that is often obliterated during expansion of the
The spores measure (5.8-)
7.0 - 9.5 (-10.9) × (5.0-) 6.8 - 8.8 (-10.5) µm and are
globose to subglobose (occasionally broadly ellipsoid)
and amyloid. Clamps are absent from bases of basidia.
Singer stated the species
occurred in forests of broad-leaved trees or in forests
of such trees mixed with conifers. Among the associated
trees, he listed beech, birch, fir, hemlock (Tsuga),
oak, pine, and spruce. In my experience, the species is
most commonly found in the northern hardwood-hemlock
forests of the New England states in the USA, the
southeastern provinces of Canada, and in the Appalachian
mountain chain at least far enough south to include the
Great Smoky Mountains National Park.
The species was described from
material collected in Massachusetts, Michigan, New York
and Virginia, with the type taken from the Michigan
material. Singer stated the species' range extended south
to Florida. It is known from the eastern USA. Its
segregation from A.
asteropus Sabo ex Romagn. was demonstrated by
Tulloss and Massart (1998). There
is some question as to whether A. aestivalis is
distinct from A. brunnescens G. F. Atk. Singer claimed that bruising/staining
occurred more rapidly in A. brunnescens and that
the radial lines of pigment often seen on the cap of the
latter species are not ever to be found in A. aestivalis.—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.
Due to delays in data processing at GenBank, some accession numbers may lead to unreleased (pending) pages.
These pages will eventually be made live, so try again later.
Tulloss and F. Massart. 1998. Doc. Mycol. 28(109-110): 73-76. [partial]
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 material.
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 not directly from the protolog of the present taxon and not cited as the work of another researcher is based on original research of R. E. Tulloss.
from type study of RET: [100/4/3] (6.5-) 7.5 - 9.5 (-10.8) × (6.0-) 7.0 - 9.0 (-10.0) μm, (L = 8.3 - 8.6 μm; L' = 8.4 μm; W = 7.8 - 8.0 μm; W' = 7.9 μm; Q = (1.0-) 1.02 - 1.14 (-1.18); Q = 1.07; Q' = 1.07), hyaline, colorless, smooth, thin-walled, amyloid, globose to subglobose, infrequently broadly ellipsoid, rarely lachrimoid, usually at least somewhat adaxially flattened; apiculus ??; contents ??; ?? in deposit.
composite data from all materail revised by RET: [200/9/6] (5.8-) 7.0 - 9.5 (-10.9) × (5.0-) 6.8 - 8.8 (-10.5) µm, (L = (7.6-) 7.9 - 8.6 µm; L’ = 8.4 µm; W = (7.2-) 7.5 - 8.0 µm; W’ = 7.8 µm; Q = (1.0-) 1.02 - 1.14 (-1.20); Q = 106 - 1.08 (-1.09); Q’ = 1.07), hyaline, colorless, smooth, thin-walled, amyloid, globose to subglobose, infrequently broadly ellipsoid, rarely lachrimoid, usually at least somewhat adaxially flattened; apiculus sublateral, truncate-conic; contents ??; ?? in deposit.
Solitary or in small groups. Michigan: Under Quercus or in hardwood forest. New Hampshire: In litter of deciduous forest. New Jersey: At 18 m elev. In sandy soil of typical Pinus rigida-Quercus barrens. Tennessee: At 795 m elev. West Virginia: With Pinus, Tsuga canadensis, and Acer pensylvanicum.
U.S.A.: MAINE— Penobscot Co. - Orono, Univ. of Maine, campus, 10.viii.1991 anon. s.n. [Tulloss 8-10-91-A] (RET 105-1).
MASSACHUSETTS—Worcester Co. - Upton, Upton St. For., 14.viii.1993 NEMF1993 participant s.n. [Tulloss 8-14-93-G] (RET 096-2).
MICHIGAN—Cheboygan Co. - E shore of Burt Lk., 18.vii.1953 Rolf Singer N667 (paratype, F 1099362); Douglas Lk., 22.vii.1953 R. Singer N735 (paratype, F).
NEW HAMPSHIRE—Hillsborough Co. - Fox St. For., 18.viii.1989 Diane Pruden s.n. [Tulloss 8-18-89-H] (RET 245-5).
NEW JERSEY—Middlesex Co. - Jamesburg Twp., Jamesburg Twp. Pk., ca. Helmetta [40°23’07” N/ 74°25’48” W, 18 m], 24.vii.1996 Britt Carlson & R. E. Tulloss 7-24-96-A (RET 200-5). Monmouth Co. - Roosevelt, North Valley Rd. bicycle path [40°12’49” N/ 74°28’19” W], 7.ix.1999 M. A. & R. E. Tulloss 9-7-99-A (RET 295-7); Upper Freehold, Assunpink Wildlife Management Area [40°12’36” N/ 74°28’42” W], 8.ix.1999 M. A. & R. E. Tulloss 9-8-99-E (RET 296-5).
NEW YORK—Otsego Co. - Oneonta, College Camp, 16.viii.1985 George Waitkins s.n. [Tulloss 8-16-85-D] (RET 101-1).
TENNESSEE—Sevier Co. - ca. Gatlinburg, GSMNP, Cherokee Orchard [35°40'31" N/ 83°29'09" W, 795 m], 12.vii.2004 R. E. Tulloss 7-12-04-B (RET 375-8).
WEST VIRGINIA—Greenbrier Co. - ca. 1.6 km W of Charmco, U.S. Rte. 60 rest stop, 9.viii.1990 Dr. M. A. Vincent 4383 (MU; RET 146-9).
Singer distinguished the present species from A. brunnescens by its reportedly slower staining reaction, by the pileus being pure white except for a yellowish disc, and by the lack of brown radial lines on the pileus.
All these characteristics may be due to the weakness or absence of a single chemical reaction in the fruiting body—perhaps something akin the tyrosinase-triggered melanin cycle common in most pigmented agarics. The presence of tyrosinase in brunnescens (of all cap colors) and A. aestivalis is insufficient to produce a visible spot test response to (e.g.) paracresol, a reagent specific for the presence of tyrosinase among all known phenoloxidases in fungi (RET, unpub. data). Hence, the process for producing staining and pileus pigmentation are both (if they are two separate processes) unknown in the North American species of stirps Brunnescens.
A sporograph comparison with A. brunnescens (note that the sample size for the latter species is presently rather small) follows:
One of the distinguishing features of the European A. asteropus is that it produces an intense positive reaction for tyrosinase when paracresol is applied to the entire surface exposed by longitudinal section of a complete basidiome. The European species has a cream to butter yellow pileus and is never virgate. A sporograph comparison is shown in the following diagram:
To date no difference has been found between nrITS sequences derived from mushrooms of the present species and those derived from material of A. brunnescens. further work is on-going.
—R. E. Tulloss
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"White American Star-Footed Amanita"
1. Amanita aestivalis, south central, New York [state], U.S.A.
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.