The following description is based on Beeli (1935).
The cap of Amanita fulvopulverulenta is 90 - 100 mm wide, flattened-convex, fleshy, with a slightly prominent umbo, with a slightly striate margin. The cap is pale pinkish brown covered with brownish-red, powdery remains of the volva
The gills are free, slightly yellowish, and somewhat rounded at the end near the stem.
Its stem is 120 - 170 × 10 - 20 mm, solid, and cylindric. The surface is fibrillose to glabrous, white or slightly tinted red. The flesh is whitish but turns pink when cut. The stem is easily separated from the cap. The stem's bulb is spindle-shaped or somewhat turnip or carrot shaped. The limb of volva on the top of the bulb is not very persistent. On the other hand, the ring on the stem is said to be persistent. This is an odd combination of characters for a species that has been thought to be assignable to sect. Amidella.
Beeli reported the spores as measuring 7 - 8 × 4 µm, amyloid, and elongate to cylindric. Gilbert's spore measurements are 7.5 - 11.3 × 3.7 - 5.0 µm.
The present species was originally described from the Democratic Republic of Congo in dry forests.
E.-J. Gilbert's comment that this species is very similar to A. goossensiae Beeli is not borne out by his own spore data (1941). Moreover, as noted above the presence of a bulb and a weak-limbed volva is unusual in sect. Amidella, while the stipe base in A. goossensiae lacks a bulb and is enclosed in a very robust volval sac—characters typical of sect. Amidella
On the other hand, the pigments, spore shape, flesh changing to pink when cut, membranous volva that has a powdery inner-layer, and narrow spores are all indicators that have been taken to indicate that a species belongs in sect. Amidella [typified by the American species A. volvata (Peck) Lloyd].
Madame Goossens' painting shows a section of a button with a very distinct bulbous base. In the somewhat macroscopically similar A. goossensiae Beeli and A. fulvosquamulosa Beeli, Madame Goossens carefully distinguished the flesh of the totally elongating stem from the strongly thickened volval sac. That she failed to do so in the case of the present species suggests that it had a true bulb. It should be noted that I have never revised dried material. If Madame Goossens' painting is correct, then A. fulvopulverulenta would be an exception to the dominant stipe and volva development in section Amidella.—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.
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 is derived from the protolog of the present taxon, (Beeli 1935), and (Gilbert 1940 & 1941).
from protolog: 90 - 100 mm wide, pale flesh-colored, plano-convex; context fibrous-fleshy, white; margin lightly striate; universal veil as brownish red pulverulence covering surface.
from protolog: free, density not described, lightly yellowish, narrowing toward the stipe, 8 - 9 mm broad; lamellulae not described.
from protolog: 120 - 170 × 10 - 20 mm, white or tinged reddish, cylindric, fibrous, glabrous, easily detachable from pileus; bulb ventricose or narrowly napiform with radicating base (per figure); context fibrous-fleshy, white, becoming pinkish when sectioned; partial veil membranous, white, thin; universal veil as limbate volva (per figure), membranous, thin, brown-red, not very persistent. [Note: A thin, ephemeral, limbate volva on a species with a persistent partial veil is not at all typical of Amanita sect. Amidella.—ed.]
from protolog: Odor strongly acrid. Taste bitter.
Beeli (1935): filamentous hyphae, thin; inflated cells terminal. [Note: It is possible that inflated cells of the volva or acrophysalides from the stipe context were perceived as included in the pileipellis.—ed.]
from protolog: 7 - 8 × 4 μm, hyaline, smooth, amyloid. [Note: Beeli's spore data often appears to be incorrect (values too low). Compare with values derived from measuring the scaled drawings of spores in (Gilbert 1940), below. Sporograph not generated.—ed.]
Beeli (1935): differs from the above by saying the spores were inamyloid—apparently an error.
Gilbert (1940 & 1941): [2/1/1] 9.0 - 9.2 (-11.5) × 4.0 - 4.6 (-5.1) μm, (Q = 1.99- 2.26), hyaline, smooth, "regular," amyloid, elongate to cylindric, at least somewhat adaxially flattened (per figure); apiculus sublateral (per figure); contents not described; white in deposit.
The powdery inner layer of the universal veil, the pigments, the color change of the context. the striate pileus margin, the narrow amyloid spores all appear to argue for placement of the present taxon in sect. Amidella. The stipe's having a distinct, radicating bulb with a fragile, limbate volva encircling the stipe base and a persistent partial veil could support placement of the present species in Amanita [sect. Lepidella] subsect. Limbatulae, in which it would be the first taxon with a pulverulent volval layer that is distinctly pigmented.
The present species raises the interesting possibility that it could be assignable to subsect. Limbatulae and be basal to sect. Amidella and represent a relict transitional form between the two groups. At any rate, it is very clear that, contrary to some past views, the present species is quite distinct from A. goossensiae and A. fulvosquamulosa.
—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.