The following is based on the description by
Neville and Poumarat (2004) and data
from RET (based on field notes concerning English
and Scottish material).
The cap of Amanita mappa is 40 - 100 mm wide,
whitish yellow to citron yellow, with pigment most
saturated in the center. A white variant is
sometimes encountered. The cap is sometimes
touched with rusty brown here and there; it is
hemispheric then convex, plano-convex, and finally
planar. It usually lacks an umbo. It is
shiny to subshiny; and, although tacky or slightly
viscid at first, it
dries quickly. Its margin is
nonstriate and nonappendiculate.
Volval remnants are absent or present as citron or
pallid submembranous patches or clusters of
breakable warts or fibrillose, concentrically
These become pale brown to brownish to brownish
white and are easily removable. The cap's
flesh is white, tinted citron
just below the cap skin when the cap surface is not
The gills are free to narrowly adnate,
rather crowded, very pale orangish white to cream to
white to citron tinted white, 5 - 10
mm broad, with a decurrent line on the stem and a
edge. The short gills are truncate to rounded
truncate to subattenuate and plentiful.
The stem is 50 - 150 × 6 - 23 mm, satiny, cylindric
or slightly narrowing upward,
stuffed becoming hollow, white (sometimes tinted
citron above the ring at, and sometimes appears to
be sheathed with pale citron yellow material.
The stipe's bulb is 20 - 40 × 21 - 40 mm and
marginate, subhemispherical to subglobose.
The stem's ring is membranous, skirt-like, rather
thin with a thickened edge, and located on the
upper part of the stem; it
is pale citron yellow when the cap is yellowish
(otherwise white) and browns in age. It is
finely striate on its upper side in young specimens
and finely flocculose on the edge and on the
underside especially near the edge. The ring
eventually collapses on the stem. The
volva is present as an (often) rather
short limb or limbs irregularly distributed on the
stipe's bulb or as a white to
browning ridge on the
outer edge of the flattened upper surface of the
bulb. The stem's flesh is white
The odor is radish-like or like freshly dug
RET spore measurements from yellow-capped material
7.5 - 10.0 (-16.0) × (6.0-) 7.0 - 8.8 (-10.4) µm and
are globose to subglobose, rarely broadly ellipsoid
or ellipsoid, and amyloid. Clamps are absent
from bases of basidia.
Spores measurements from yellow-capped specimens,
a larger sample of Neville and Poumarat
are 7 - 9 (-9.5) ×
6 - 8.5 (-9) µm and are globose to subglobose to
RET spore measurements from white-capped material
are (7.0-) 7.6 - 8.5 (-9.0) ×
(6.5-) 7.2 - 7.9 (-8.0) µm and are globose to
subglobose, rarely broadly ellipsoid or ellipsoid,
and amyloid. Clamps are absent from bases of
Spore measurements from white-capped specimens based
on a larger sample of Neville and Poumarat
(7.5-) 8 - 9.5 (-10) × (6.5-) 7 - 8.5 (-9) µm and
are globose to subglobose to broadly ellipsoid,
This species (both color variants) is known from
Europe and western Asia. Neville and Poumarat
state that this mushroom may occur up to an altitude
of 1200 m from spring to late autumn in Europe.
These authors include an extended list of potential
host trees including pines (e.g., Pinus
pinaster and P. strobus) spruces
(e.g., Picea abies) as well as broad-leafed
species such as birch (Betula), Chestnut
(Castanea sativa), European Beech (Fagus
sylvatica), alien eucalypts (e.g.,
Eucalyptus glabulus), and oaks
(e.g., Quercus suber). This
species will be found
in field guides or species list under a variety of
names such as A.
citrina, A. citrina var. alba,
A. bulbosa, or A. bulbosa var.
citrina. The color variants of A.
mappa do not
correspond to genetically separable
groups. The correct name for the species is
the one used to designate this page.
The mushrooms known as "A. citrina" in North
America are at least three distinct species, one of
which is A.
Whe when temperatures
approach freezing, all the known North American
species may exhibit lavender or deeper purple
bruising). This color change is not reported
for the present species.
citrinus Gunnerus. 1772.
Fl. Norveg. 2: 126. [The publication
date on this name is based on the research of
Pfister et al. (1990.
Mycologia Mem. 17: 53). This
information was re-examined and clarified at our
request (Dr. D. H. Pfister, pers. comm.): The date
1776 appears on some copies of this work.
This is the date of a re-issue of the work with
contents identical to those of the 1772
var. [B] citrina (Schaeff.) Pers. 1818.
Trait. Champ. Comest.: 180, pl. 2
(fig. 1). [A. venenosa is a nom.
dub. Selection of a type would be
var. citrina Gillet.
Champ. (Hyménomyc.) Croiss. France:
36. [Misapplication to Amanita
phalloides var. b albus
Duby in DC. 1830. DC. Bot. Gall.,
2e ed., 2: 850. [Misapplication.]
≡Agaricus (Amanita) mappa var.
minor Fr. 1874.
Hymenomyc. Eur.: 19.
≡Amanita mappa var. minor Sacc.
Syll. Fung. 5: 11.
≡Amanita mappa var. minor Killerm.
Denkschr. Bayer. Bot. Ges. Regensburg
18(neue Folg. 12): 5. [Not definitely
accepted by author. ICBN §34.1]
=Amanita citrina var. alba (Quél.)
E.-J. Gilbert. 1918.
Gen. Amanita Pers.: 67. [Note:
Numerous authors cite the basionym as originated
by W. C. Price; however, while he mentioned a white
variety, he never named it.]
≡Amanita citrina f.
alba Quél. 1892. C. R. Assoc. Franc.
Avanc. Sci. 20(2): 467.
≡Amanita citrina f.
alba (Quél.) E.-J. Gilbert. 1918.
Gen. Amanita Pers.: 64. [Superfluous
≡Amanita citrina f.
alba (Quél.) Veselý. 1933.
Ann. Mycol. 31(4): ??. [Superfluous
≡Amanita bulbosa var. alba Pers.
nom. inval. 1818.
Trait. Champ. Comest.: 179.
[Replacement for autonym of type variety.
ICBN §11.6, §32.7] [For the same reason, the
type selected by Neville and Poumarat (2004) must
be rejected because Schaeffer's plate is required
to be the holotype of Agaricus bulbosus
Schaeff. See "holotypes" data field below.]
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.
Agaricus citrinus—Neville and Poumarat. 2004. Fungi Europeaei 9: 789.
Neville and Poumarat. 2004. Fungi Europaei 9:
This page is being
rebuilt. Please be patient.
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 Dr. Z. L. Yang or another researcher is based upon original research by R. E. Tulloss.
60 - 70 mm wide, very pale citron yellow (e.g., paler
and a little greener than 1A2) or entirely white,
unchanging when cut or bruised, hemispheric at
first, then planoconvex, sometimes subumbonate,
shiny to subshiny,
glistening under lens, tacky to dry; context
white, usually unchanging, sometimes with faint
brown tint under
pileipellis in old specimens, sometimes with
waterlogged spots over stipe, 4 - 7 mm thick
above stipe, thinning evenly to margin;
nonappendiculate, incurved at first, finally
slightly decurved, with pileipellis exceeding ends
of lamellae; universal veil absent or
as cluster of minutely fibrillose warts and/or
patch(es) of varying size (up to 12.5 mm across) or
as concentrically arranged fibrillose
scales, white at first, becoming brown from edges
inward (sometimes before partial veil separates
from pileus margin), detersile.
free to narrowly adnate with slight decurrent tooth
and (occasionally) faint decurrent line
(10× lens), subcrowded, very
pale orangish white to cream to pale cream in mass,
off-white to off-white to very pale grayish white,
pale citron yellow to very pale slightly sordid
yellow in side view, unchanging when cut or bruised,
5 - 10 mm broad, ??;
lamellulae subtruncated to rounded truncate to
rounded subtruncate to subattenuate, plentiful,
52 - 133 × 9 - 13 mm, white, sometimes becoming
dingy or distinctly brown from handling, satiny,
narrowing upward slightly, barely to distinctly
flaring at apex, decorated with longitudinal
striation (fine or marked) and raised fibrils, with
surface sometimes splitting into fibrillose recurved
bulb subglobose to globose, subabrupt,
20 - 32 × 21 - 36 mm, soft, easily compressed;
context white, unchanging when cut or
bruised, white in larva tunnels, hollow or stuffed
in upper portion and stuffed or solid below, with
1+ - 3+ mm wide central
cylinder, with insets tunnels concolorous;
partial veil superior to subsuperior, pale
citron yellow or white (when pileus white),
sometimes browning with age (especially at edge),
membranous, skirtlike, collapsing, with edge
thickened, with upper side faintly striate,
with under side radially fibrillose;
universal veil as short limb or limbs
(sometimes of uneven height) or
slight ridge around top of bulb, white, browning.
Odor faintly or distinctly of radishes or of
newly dug potatoes, especially in bulb context. Taste not recorded.
Specimen with yellow pileus (RET): Spot test for
laccase (syringaldazine) - negative throughout
basidiome (mature specimen). Spot test for
tyrosinase (paracresol) - slowly positive in
sectioned pileipellis, small spot along juncture of
gill and pileus context, volval limb above stipe's
bulb, and small spot on lower stipe surface, in
approximately that order (mature specimen).
Test voucher: Tulloss 9-6-88-J.
Specimen with white pileus (RET): Spot test
for laccase (syringaldazine) - negative throughout
basidiome (sporulation just beginning). Spot
test for tyrosinase (paracresol) - minimal positive
reactions in warts on pileus, volval limb, and
external surface of bulb (specimen with sporulation
beginning). Test voucher: Tulloss
Specimen with white pileus (RET): [20/1/1] (7.0-)
7.6 - 8.5 (-9.0) × (6.5-) 7.2 - 7.9 (-8.0) μm,
(L = 8.1 mu;m; W = 7.6 μm; Q =
(1.03-) 1.04 - 1.13 (-1.14); Q = 1.07),
hyaline, colorless, smooth, thin-walled, amyloid,
globose to subglobose, often at least somewhat
adaxially flattened; apiculus sublateral,
cylindric; contents granular to
multiguttulate; ?? in
Solitary to subgregarious. Scotland: In sandy loam under leaf litter in ancient, pure stand of Fagus sylvaticus.
Weiss et al.
voucher for sequencing: GERMANY:
BADEN-WÜRTTEMBERG—Tübingen, s.d. unkn.
coll. s.n. (HKAS 31449).
Material with yellow pileus (RET):
GERMANY: ??—near Berlin
(location withheld), 14.ix.2013 R. K. Schumacher s.n.
(RET 573-8, nrITS).
VESTFOLD—Larvik - Bøkeskjogen,
27.vii.1978 G. Gulden 76/78
(O; RET 308-8).
SCOTLAND—Grampian Region - Dyke & Moy,
Darnaway Estate, 6.ix.1988 G. & S. Kibby s.n.
[Tulloss 9-6-88-E] (RET 107-5), Bernice Fatto, M. A.
King & R. Tulloss 9-6-88-I (RET 107-8), R.
Roper s.n. [Tulloss 9-6-88-J] (RET 107-9), R.
Roper & Roy Watling s.n [Tulloss 9-6-88-G]
Material with white pileus (RET):
SOUTH BOHEMIA—Stará Řeka Nature Reserve, 2.x.2006
Dr. J. Borovička 23 (RET 406-1).
FRANCE: GIRONDE—Le Porge,
16.xi.1997 F. Massart 97067 (in herb. F. Massart;
UNKN. PROV.—unkn. loc., 12.xii.2011
Carmine Lavorato 111212-18 (in herb. C. Lavorato;
Region - Dyke & Moy, Darnaway Estate, 6.ix.1988 R.
Roper & R. Watling s.n. [Tulloss 9-6-88-G]
(RET 107-7), Bernice Fatto,
Mary A. King & R. E. Tulloss
[Tulloss 9-6-88-I] (RET 107-8), G. Kibby s.n.
[Tulloss 9-6-88-K] (RET 108-4),
R. Roper s.n. [Tulloss 9-6-88-L] (RET 108-2).
This is as good a place as any to discuss why using the
spore data from ( Neville and Poumarat 2004) is not entirely
workable in these pages. One significant problem
occurs in their spore data for taxa (like the present
one) with globose to subglobose spores. Here is
the set of data they provide for the present taxon
(converted to RET's notation): [80/-/-] 7.0 - 9.0 (-9.5)
× 6.0 - 8.5 (-9.0) μm, (L' = 8.0 μm; W' =
7.8 μm; Q = 1.0 - 1.17 (-1.26); Q = 1.0 - 1.03;
Q' = 1.02).
Compare the spore data presented immediately above to
the spore data reported in the "basidiospores" data
field, further up the page. Focus on the range of
Q and, then, on the range of Q and the value of
Q'. If we eliminate the upper and lower
extreme values of Q in the two sets of data, we have Q
= 1.05 - 1.15 (RET) and Q = 1.0 - 1.17 (N & P).
RET's Q' (1.10) is precisely at the midpoint of
the first reduced range. In contrast, N & P's
Q' (1.02) is strikingly offset to the low end of
the N & P range. In fact, the only way this
can be true is if there were far more spores with
Q < 1.02 than there were spores with Q between 1.02
and 1.17. What can cause such a striking
difference in the two sets of data?
The most probable cause is not insisting that the
spores that are measured be in lateral view.
Without the procedure of measuring only those spores
that are found by a fixed search pattern and are
in lateral view when found and measured, the majority
of spores measured will be foreshortened (one end is
closer to the scope's objective than the other) and may
appear broader than they would in lateral view, which
is the only view in with the adaxial flattening of
Amanita spores is clearly viewed (thus reducing spore width as much as possible).&
After evaluating the Neville and Poumarat (2004) data
for the present species and other globose to subglobose
spored species, RET decided not to include it in the
basidiospore data fields for such species (and,
consequently, not to have sporographs generated for such
—R. E. Tulloss
Information to support the viewer in reading the content of "technical" tabs
can be found here.
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.