The cap of A. amerifulva is 45 - 60 mm wide,
fulvous to grayish orange to brownish orange to orange brown, slightly darker (dark fulvous) over disk, and unchanging when bruised or cut. The cap is campanulate at first; it becomes convex and then planoconvex with a broad umbo. The flesh of the cap is white to pale cream, sometimes with fulvous tint in the upper part or just near the cap's skin. It is mostly unchanging when bruised or cut. The cap margin is striate for one-third to one-half of the cap's radius, sometimes splitting, and nonappendiculate. Volval remnants are almost always absent.
The gills are free to occasionally narrowly attached to the stem, subcrowded to crowded, white to pale cream to cream to very pale orangish or yellowish cream when viewed in mass and white to off-white to pale cream to cream in side view, unchanging when cut or bruised, with their edges minutely decorated. Short gills are truncate to subtruncate to truncate with attenuate tooth at pileus context, plentiful, of diverse lengths, unevenly distributed, and occasionally connected to stem rather than to the cap margin.
The exannulate stem is 90 - 124 × 7 - 8 mm, white to cream to pale yellowish to very pale fulvous, occasionally darkening slightly from handling (especially with surface fibrils becoming fulvous or darker); the stem narrows from bottom to top, and may flare (but only very slightly) at the top. The stem's flesh is white to off-white to slightly orangish white; and there may sometimes be rusty spots in the very base of the stem; it is hollow with a lining or occasional cross walls of white cottony fibrils. The volva at the stem's base is saccate, membranous, soft, rather firm, and white; it develops ochraceous or rusty or grayish orange (6B6) tinges (at first in the upper part of the limb, then spreading downward) and occasionally becomes entirely grayish orange.
The odor is faintly fungoid or indistinct to absent. The taste has not been recorded.
The spores measure (8.0-) 9.2 - 12.0 (-14.0) × (6.8-) 8.8 - 11.2 (-12.5) µm, are globose to subglobose (occasionally broadly ellipsoid) and inamyloid. Clamps are absent from bases of basidia.
This species is the one most commonly (and incorrectly) referred to Amanita fulva in Northeastern North America—it is very common throughout the eastern United States and southeastern Canada.
It is found in many forest types. Among its possible ectomycorrhizal associates are pine (Pinus), Canadian hemlock (Tsuga canadensis), birch (Betula), red oak (Quercus rubra), basswood (Tilia). American beech (Fagus grandifolia), and spruce (Picea). Occasionally, mushrooms of this species are found in very rotten wood of old stumps through which the fungus has grown upward from surrounding soil. Tolerance for wet conditions is indicated by one collection's having been collected in a cranberry bog.
"American Orange-Brown Ringless Amanita"
elision of "America" and "fulva"; hence, American fulva.
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Olive text indicates a specimen that has not been
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where data is missing or uncertain.
The following is based upon
original research by R. E. Tulloss.
45 - 60 mm wide, fulvous to grayish orange (6B3-4) to
brownish orange (6C4) to orange brown (5B6, 6C6),
slightly darker (dark fulvous—e.g., 7E-D7) over disk,
unchanging when bruised or cut (or edges of
pileipellis slightly brown in old wounds),
campanulate at first, becoming convex and then
planoconvex with broad umbo, subshiny to dull,
subviscid or tacky when moist; context white to
pale cream, sometimes with fulvous tint in upper part
or just near pileipellis, infrequently with a few
rusty spots, unchanging when bruised or cut, sometimes
rather brittle, 4.5 mm thick at stipe, thinning
evenly for about two-thirds to three-quarters of
radius, then a membrane to margin; margin
subtuberculate to sparsely tuberculate-striate (0.35 - 0.5R), sometimes becoming rimose to fissurate, nonappendiculate; universal veil almost always absent.
free to occasionally narrowly adnate, without decurrent line on stipe or with faint very short line (lens), subcrowded to crowded, white to pale cream to cream to very pale orangish or yellowish cream in mass and white to off-white to pale cream to cream in side view, unchanging when cut or bruised, 4.5 - 7 mm broad, with edge minutely fimbriate; lamellulae truncate to subtruncate to truncate with attenuate tooth at pileus context, plentiful, of diverse lengths, unevenly distributed, occasionally connected to stipe rather than to margin.
90 - 124 × 7 - 8 mm, white to cream to pale yellowish (4A3-4) to very pale fulvous, occasionally darkening slightly from handling (especially with surface fibrils becoming fulvous or darker), narrowing upward, barely or not flaring at apex, pruinose or finely fibrillose above, faintly longitudinally striatulate (lens) and satiny (lens) to fibrillose or smooth below; context white to off-white to slightly orangish white, sometimes with rusty spots in very base of stipe, hollow with lining or occasional cross walls of white cottony fibrils, with larva tunnels concolorous, with central cylinder 4 - 4.5 mm wide; exannulate; universal veil as saccate volva, membranous, soft, rather firm, white, developing ochraceous or rusty or grayish orange (6B6) tinges (at first in the upper part of the limb and spreading downward), occasionally becoming entirely grayish orange, edges of limbs occasionally brown, 32 - 38 mm from stipe base to highest point of limb, 17 - 20 mm wide, with limb 1- - 2 mm thick at midpoint of free portion; limbus internus ??.
Odor faintly fungoid or indistinct or absent. Taste not recorded.
L-tyrosine spot test for tyrosinase - ?. Paracresol spot test for tyrosinase - ?. Syringaldazine spot test for laccase - ?.
wst-near = 15 - 20 (-35) µm; wst-far = 40 - 55 µm; 4± cells deep, comprised of inflated and partially inflated cells in branching structure, soon with major axis roughly perpendicular to central stratum, with most basidia arising from inflated cells, occasionally with an elongate cell reaching from central stratum to base of basidium.
44 - 65 × 12.0 - 16.0 µm, ?-sterigmate, with sterigmata up to ? × ? µm; clamps not observed.
[160/8/8] (8.0-) 9.2 - 12.0 (-14.0) × (6.8-) 8.8 - 11.2 (-12.5) µm, (L = (10.0-) 10.5 - 11.2 µm; L’ = 10.6 µm; W = (9.2-) 9.8 - 10.2 µm; W’ = 9.9 µm; Q = (1.0-) 1.02 - 1.14 (-1.22); Q = 1.06 - 1.09 (-1.10); Q’ = 1.08), hyaline, colorless, thin-walled, smooth, inamyloid, globose to subglobose, occasionally broadly ellipsoid, at least somewhat adaxially flattened; apiculus sublateral, at times rather prominent, cylindric to truncate-conic; contents monoguttulate; white in deposit.
Very common throughout eastern United States and southeastern Canada, found in many forest types. New Jersey: ?. New York: In open woods of Abies and Picea, near Sphagnum bog. West Virginia: in forest of Pinus, Tsuga canadensis, and Acer pennsylvanicum or in forest dominated by Betula lutea f., T. canadensis, Quercus rubra, and Tilia sp. or in boggy to very wet, dark loam with T. canadensis, B. lutea, Fagus grandifolia, and Picea or at 1220 m elev. in forest of old growth Picea and B. lutea or in deep moss under Picea rubens.
Occasionally found in very rotten wood of old stumps. Tolerance for wet conditions is further indicated by BPI 14713 having been collected in a cranberry bog.
CONNECTICUT—Middlesex Co. - E. Haddam, Devil's
Hopyard St. Pk. [41.4756° N/ 72.3403° W, 72 m],
3.ix.2011 Sandy Sheine s.n. [Tulloss 9-3-11-P]
(RET 490-4), 4.ix.2011 Rhoda Roper s.n. [Tulloss
9-4-11-B] (RET 492-1).
MAINE—Penobscot Co. - Bangor, Prentiss
Woods, 12.viii.1991 participant NEMF91 s.n.
[Tulloss 8-12-91-D] (RET 030-6).
Co. - Jamesburg Twp., Jamesburg Twp. Pk., ca.
Helmetta [40°23’07” N/ 74°25’48” W], 24.vii.1996 Britt Carlson & R. E. Tulloss 7-24-96-F (RET 200-9). Monmouth Co. - Shark River St. Pk. [40°12’18” N/ 74°05’44” W, 16 m], 13.ix.1998 NJMA foray participant s.n. [R. E. Tulloss 9-13-98-D] (RET 287-9). Morris Co. - Hackettstown Reservoir, 25.vii.1984 G. Kibby, J. Richards, R. Peabody & R. E. Tulloss 7-25-84-J (RET 053-1). Ocean Co. - Waretown [39°47’12” N/ 74°11’50” W], 15.x.1993 Cornelius Hogenbirk 13 (RET 118-5). Sussex Co. - Stokes St. For., 7.vii.1985 David C. Tulloss & R. E. Tulloss 7-7-85-C (RET 053-6), D. C., M. A. & R. E. Tulloss 7-7-85-D (RET 054-7); Stokes St. For., Kittle Field Recreation Area [41°12’23” N/ 74°46’30” W], 28.ix.1997 Laura G. Weishaupt & R. E. Tulloss 9-28-97-B (RET 271-1).
NEW YORK—Franklin Co. -
Floodwood Mtn. Rd. [44.3476° N/ 74.4424° W, 501 m],
21.viii.1987 Ray La Sala s.n. [Tulloss 8-21-87-J]
(RET 017-2); E of Floodwood Mtn. Rd., 22.viii.1987
J. & S. Arnold, G. Flanz & R. E. Tulloss
8-22-87-G (RET ??),
22.viii.1987 R. E. Tulloss 8-22-87-H (RET 017-3),
-I (RET ??);
Jenkins Mtn. Rd., 22.viii.1987 NEMF foray
participant s.n. [Tulloss 8-22-87-D] (RET 019-3);
Paul Smith's [44°26'02" N/
74°15'06" W, 500 m], 20.viii.1987 NEMF foray
participant s.n. [Tulloss 8-20-87-A] (RET 017-6),
[Tulloss 8-20-87-B] (RET 018-7), 21.viii.1987 D. C.
& R. E. Tulloss 8-21-87-D (RET 017-1),
21.viii.1987 R. E. Tulloss 8-21-87-C (RET 017-4),
21.viii.1987 Randy Weidner s.n. [Tulloss 8-21-87-E]
(RET 017-5). Madison Co. - unkn. loc.,
11.ix.2010 Eric Smith s.n. [www.mushroomobserver.org
(RET 482-5). Unkn. Co. - Adirondack Pk.,
21.viii.1987 NEMF foray participant s.n. [Tulloss
8-21-87-O] (RET 018-4).
NORTH CAROLINA—Macon Co. - SW of
Highlands, Glen Falls, 21.vii.2008 Jay Justice s.n.
PENNSYLVANIA—Pike Co. - Dingman's Ferry,
Pocono Environmental Education Ctr. [41°10'17" N/
74°54'52" W, 235 m], 20.vi.1981 Mary A. King &
R. E. Tulloss 6-20-81-E (RET 176-3), 21.vi.1981
M. A. King & R. E. Tulloss 6-21-81-R
(RET 168-4), 21.vi.1986 M. A. King, R. E. Tulloss,
et al. 6-21-86-E (RET 245-8); Lehman Twp., Egypt
Mills [41°07'33" N/ 74°57'29" W, 130-195 m],
26.vi.1985 R. E. Tulloss 6-23-85-B
(RET 055-7). Union Co. - R. B. Winter St.
Pk., 13.viii.1984 D. C., Mark H., & R. E.
Tulloss 8-13-84-D (RET 008-3).
TENNESSEE—Blount Co. - GSMNP, Cades Cove,
picnic area, 27.ix.2006D. J. Lodge & R. E.
Tulloss 9-27-06-G (RET 401-6). Cumberland
Co. - Cumberland Mtn. St. Pk., W side of loop tr.,
19.vii.2008 J. Justice s.n. (RET 435-6).
Sevier Co. - ca. Gatlinburg, GSMNP, Fork Ridge
trailhead [35°35'24” N/ 83°28'09” W], 13.vii.2004
mycoblitz participant s.n. [Tulloss 7-13-04-D]
(RET 378-5); Grotto Falls trailhead [35°40'52” N/
83°27'45” W], 12.vii.2004 Matt Kierle s.n. [Tulloss
7-12-04-X] (RET 376-4); ca. Gatlinburg, GSMNP,
Indian Gap [35°36'34” N/ 83°26'19” W], R. E.
Halling s.n. [Tulloss 7-13-04-L] (RET 377-1).
VERMONT—Bennington Co. - ca. Bennington,
28.viii.1981 R. E. Tulloss 8-28-81-A (RET 166-7);
ca. Bennington, Bennington Fish Culture Stn.
[42°51'10" N/ 73°10'12" W, 288 m], 24.viii.1980
M. A. King & R. E. Tulloss 8-24-80-B (RET
VIRGINIA—Unkn. Co. - Shenandoah Nat. Pk.,
s.d. "RRGS" 25 (LFCC; RET 143-9).
WEST VIRGINIA—Greenbrier Co. - woods
above rest stop along U.S. Rt. 60 ca. 1.6 km W of
Charmco, 9.viii.1990 M. A. Vincent 4388 (MU
F38504). Pocahontas Co. - Monongahela Nat.
For., ca. Highland Scenic Hwy., 31.vii.1982 G.
Bills 421 (BPI 900737); Monongahela Nat. For.,
26.vii.1977 K. H. & Kathleen McKnight s.n. (BPI
14713). Randolph Co. - Gaudnier Scenic Area,
26.ix.1992 S. L. Stephenson, R. P. Bhatt & A.
Kumar A4 (FWVA; in herb. R. P. Bhatt).
Tucker Co. - Abe Run Tr., Canaan Valley St. Pk.,
6.viii.1992 Mary A. King, E. H. Tulloss, J. C.
Tulloss, S. E. K. Tulloss & R. E. Tulloss
8-6-92-A (RET 120-1),
6.viii.1992 R. E. Tulloss 8-6-92-B (RET 120-2).
The following figure provides sporograph comparisons between the present possible taxon and two formally named taxa: A. fuligineodisca and A. fulva.
Amanita amerifulva has pigmentation very similar to that of another provisional taxon, A. daimonioctantes. The following figure provides sporograph comparison of the two possible taxa:
Other sporograph comparisons of interest occur on the techtabs for A. sp-N44 and A. sp-N46.
—R. E. Tulloss
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can be found here.
"American Orange-Brown Ringless Amanita"
1. Amanita amerifulva, Sussex Co., New Jersey, U.S.A.
2. Amanita amerifulva, Bloomingdale Bog, Franklin Co., New York, U.S.A.
RET - (1) Sussex County, New Jersey, U.S.A.
(2) Bloomingdale Bog, Franklin County, New York, 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.