The following description is based on the original
description of Amanita infusca (≡A.
and (Gilbert 1940 &
The cap of Amanita infusca is
70 - 120 mm wide, subcylindric at first,
expanded-convex, fleshy, glabrous, with
a long striate margin. The center of the cap is
The cap is blackish brown with a coal-black
center. The volva is absent.
The gills are free, pale, very pale pinkish-white,
10 mm broad, and pointed at the end near the stem.
Its stem is 170 - 200 × 8 - 11 mm, streaked with dark
eventually hollow, and tapering upward. The
ring is placed above the middle of the stem and is
skirt-like, membranous, and umber-brown. The
volva is membranous, thick, whitish, and
saccate. The stem's flesh is white.
The odor and taste of A. infusca are acrid.
The spores of A. umbrina measure 9.1- 10.2 × 6.5 - 7.5
µm and are ellipsoid and inamyloid. The bases
of basidia probably bear clamps.
The present species was originally described from the
Republic of Congo in association with
Madame Goossens depicts the fibrils of the stem as
significantly browner than the very dark cap and
ring. In her painting, the volval sac is quick
thick at the base and the thinner upper part is
broadly opened and collapsing like a deflating
basketball. She also shows that the underside
of the annulus, at least at first, is pallid with
flecks that are concolorous with the colored
fibrils on the stem—more reddish brown than
fuliginous or dark brown.
Amanita infusca sensu Pegler and Shah-Sm.
a somewhat similar mushroom from Zambia, but, given
the state of knowledge of A. infusca, the
Zambian material may be an undescribed
species. The cap, rather than being coal
black in the center, is sometimes yellowish-brown;
the stem is often shorter than the cap's diameter;
the annulus is described as pale to reddish-brown;
the saccate volva has a reddish-brown margin; the
odor is very faint; and the spores are larger, so
far as can be told, although similarly
shaped.—R. E. Tulloss
E.-J. Gilbert ex Singer. 1951 ["1949"].
Lilloa 22: 385, t. 10.
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 information is derived from the
protolog of the present species and from
& 1941). RET interpreted
associated illustrations to increase the detail
of the descriptions.
protolog: 70 - 120 mm wide,
fuligineous, fuiligineous-black over
disc, a little less dark toward
margin, initally ovoid then campanulate,
eventually plano-convex and centrally depressed. not
context white, firm, unchanging [per figure],
thickest above stipe, thinning evenly toward margin
for two-thirds to three-quarters of radius, then
membranous to margin [per figure];
margin long striate (0.35-0.55R),
nonappendiculate; universal veil
protolog: free, density not
recorded, white to pale pinkish, 10±
mm broad, broadest at ca two-thirds length from
stipe [per figure], attenuate toward stem, rounded
[per figure]; lamellulae excavate truncate
[Note: Without comment, Beeli (1935) replaced
"whitish" ("lamellis...albidis") in the
protolog with "light pink" ("Lamelles...légèrment
rosées"). This change is in agreement with
the 1935 reproduction of the Goossens watercolor of
this species in which the lamellae are distinctly
pink in the cross-section of a mature
specimen. Gilbert (1941) followed Beeli's
1935 description. It should be noted that
Goossens represented the lamellae of an immature
specimen as white.—ed.]
protolog: 170 - 120 × 8 -
11 mm, with pallid ground color underlying
moderately dense layer
of dark red-brown fibers (redder than
pileus in Goossens' watercolor), narrowing upward;
context white, firm, becoming hollow;
partial veil superior, membranous,
persistent, fuliginous, infundibuliform at first,
then pendent. spotted below; universal veil
thick, white on exterior, attached to sides of
stipe well above
stipe base in Goossens' watercolor, with long free
protolog: [-/-/-] 9 - 10 × 6
μm, (approx. Q = 1.50 - 1.67), hyaline, smooth,
inamyloid, ellipsoid; color in deposit
unknown. [Note: A sporograph cannot be
generated from this data.—ed.]
[5/1/1] 9.1- 10.2 ×
6.5 - 7.5 μm, (L = 9.6 μm; W =
6.9 μm; Q = 1.29 - 1.51; Q = 1.40),
hyaline, smooth, inamyloid, ellipsoid;
apiculus sublateral; contents not
descibed; color in deposit unknown.
[Note: Spore measurements are taken from the five
drawings of (Gilbert 1940: tab.
VII (fig. 6)) that are in apparent lateral
protolog: Rare. In
tropical forest with Gilbertiodendron
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.