Fruiting body dimensions are taken from Traverso (1999).
All parts of the fruiting body bruise/stain reddish or orangish brown when damaged.
The cap of A. asteropus is 60 - 120 mm wide and ranges from cream
with a butter yellow tint in the center to ivory white to
pale butter yellow. When moist it is slightly viscid. At
first the cap is bell-shaped, then convex, and finally
planar with an umbo. It can be convex in age. The volva
is often absent from the cap but sometimes appears as
submembranous, pale-ochraceous plaques.
The gills are free and white at first, then cream.
The stem of A. asteropus is 100 - 150 × 15 - 20 mm, white to pale
yellow, and bears a superior annulus that is white above
and may be pale yellow below. Some sources say that the
annulus is sometimes quite fragile. The stem's bulb is
roughly hemispherical and split vertically on the sides
giving it a star-shaped cross-section when cut
perpendicular to the axis of the stem. The volva is white
to yellowish at first and is fragile and easily left in
the substrate when the species is collected.
Amanita asteropus (especially in the base of the stem) has the odor of
radish or raw potato when young. It has no appreciable taste.
The white spores measure (6.8-) 7.3 - 10.1 (-14.5) × (6.0-) 6.9 - 9.2 (-11.6) µm
and are globose to subglobose (infrequently broadly
ellipsoid or ellipsoid) and amyloid. Clamps are absent from the bases of basidia.
The species was originally described from France (Gironde) and is known from
southern Europe. Oddly, neither author gave macroscopic
dimensions for any part of the fruiting body.
Amanita asteropus is associated with oak, either in pure groves or in mixed forests.
Its segregation from A. aestivalis Singer was demonstrated by Tulloss and Massart
species differ at least in the color of the fruiting body
and in their reactions to macrochemical tests (e.g.,
when 1% paracresol solution is applied to a cross-section
of the fruiting body of A. aestivalis there is
no reaction; but when the same is done to A.
asteropus, the entire cross-section becomes
red-brown—positive for the presence of tyrosinase).
Photo courtesy of Francis Massart (southern France).
Sabo ex Romagn. 1982. Bull. Trimestriel Soc. Myc. France 98(2): 165.
"European Star-Footed Amanita"
≡Amanita asteropus Sabo in Sabo & F. Massart nom. inval.1963. Proc.-verb. Soc. Linn. Bordeaux 100: 92-96. [Lacking Latin diagnosis and specification of holotype. ICNB §36.1, §37.1]
≡Amanita asteporus Sabo ex Anon. 1983. Bull. Soc. Linn. Bordeaux 11(1): 34. [Superfluous combination.]
≡Amanita porphyria var. asteropus (Sabo ex Romagn.) Garcin comb. inval1984. Amanites Europ.: 189. [Published in indelible autograph after 1 Jan. 1953. ICBN §30.1-.2, §32.1(a).]
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.
partial: Massart, F. 1964. Proc.-verb. Soc. Linn. Bordeaux 101: 71.
partial: Tulloss and F. Massart. 1998. Doc. Mycol. 28(109-110): 73-76.
Neville and Poumarat. 2004. Fungi Europaei 9: 780-786.
F. Massart. 1980. Bull. Sect. Mycol. Soc. Linn. Bordeaux 8: 8, 10-12, figs. 1-7, 9-11.
F. Massart. 1984. Approche Gen. Amanita: 69, pl. 16.
F. Massart. 1986a. Boll. Assoc. Micol. ed Ecol. Rom. 3(8-9): 39, 41, 43, 46-47, color plate & figs. 1-5, 7-8.
F. Massart. 1987. Bull. Soc. Linn. Bordeaux 15: 10, pl. 3.
F. Massart. 1990. Connaître Champ.: 11.
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 not directly from the protolog of the present taxon and not cited as the work of another researcher is based upon original research by R. E. Tulloss.
from protolog: ivory, always spotted with wine-colored or reddish or brown in center, at first obtusely conic, then expanded with rounded or (at length) flattened umbo; context thick, white except sometimes slightly pinkish gray under pileipellis; margin not described; universal veil sometimes present as one or several plaques, submembranous, whitish or ochraceous.
from protolog: white, browning where bruised, sometimes spotted as on pileus, narrowing upward; bulb splitting [longitudinally] and taking star-like form [viewed from above]; context hollow; partial veil membranous; universal veil not described. [Note: the universal veil and bulb are conflated in the original text; the abrupt character of the bulb is not mentioned.—ed.]
from protolog: Odor like
that of A. mappa,
but weaker. Taste not recorded.
from protolog: 8.5 - 10 (-12) μm diam, amyloid, subglobose. . [Note: Insufficient information to generate sporograph.—ed.]
composite from all material revised by RET: [351/17/8] (6.8-) 7.3 - 10.1 (-14.5) × (6.0-) 6.9 - 9.2 (-11.6) µm, (L = (7.6-) 8.2 - 9.1 (-9.3) µm; L’ = 8.6 µm; W = (7.0-) 7.6 - 8.4 (-8.6) µm; W’ = 8.0 µm; Q = (1.0-) 1.02 - 1.16 (-1.34); Q = (1.05-) 1.07 - 1.10; Q’ = 1.08).
from protolog: In sandy forest
or in calcareous clay. With
RET: Under Quercus robur or in forest with
from protolog: FRANCE:
UNKN. DÉP.—unkn. loc., s.d., unkn. coll.
s.n. [H. Romagnesi 57.310] (holotype, in herb.
H. Romagnesi => PC).
7.vii.1993 Francis Massart 93055 (in herb.
Massart; RET 259-4); La Brède, Château
La Sauque, 27.vi.1997 Francis Massart 97031
(in herb. Massart; RET 262-2); Gradignan,
Mandavit [24 m elev.], 7.vii.1993 F. Massart 93054
(in herb. Massart; RET 259-5),
vii.1996 F.Massart 96021
(in herb. Massart; RET 259-6, nrITS seq'd.), 27.vi.1997 Francis
Massart 97031 (RET 262-2),
30.vi.1997 F. Massart 97032 (in herb. Massart;
vii.2000 F. Massart 20005
(in herb. Massart; RET 342-3, nrITS seq'd.).
Médoc, Segonne, 2.viii.1958 F. Massart
58-01 (RET 020-8), F. Massart 58001 (in
herb. Massart; RET 259-7).
INDRE-ET-LOIRE—Forêt de Russy,
Carrefour de l’Étoile, 6.ix.2015 Pierre-Arthur
Moreau 15090601 (RET 730-2, nrITS &
LES LANDES—Mont de Marsan,
15.viii.1991 F. Massart 91 AI 1/7 (RET 032-5).
—R. E. Tulloss and F. Massart
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.