The following description is based on Jenkins (1977).
The cap of Amanita monticulosa is 50 - 80 mm wide, convex to plano-convex, occasionally with slight umbo, [sometimes?] cracking into irregular regions, slightly viscid when moist, thin fleshed, with faintly or nonstriate margin. The volval remnants are present as angular, pyramidal, or truncate warts becoming more flocculent towards the margin of the cap.
The gills are free, ventricose, and distant from the stem.
The stem is 30 - 60 × 4 - 8 mm, slightly tapering upward, white, stuffed to hollow, fibrillose, with scaly to felted-subfloccose volval patches at the top of the bulb. The basal bulb is subglobose to ovoid. The ring is thick, distant from the top of the stem, and floccose [on its bottom?].
We know of no information about odor or taste for this species.
The spores measure 10 - 11.2 (-12.5) × 7 - 8 (-9) µm and are broadly ellipsoid to ellipsoid and are inamyloid.
Originally described from South Carolina, USA, from sandy soil.
Jenkins comments that this species differs from taxa similar to Amanita pantherina (DC. : Fr.) Krombh. because the volva is not ocreate. He mentions that the species is distinct from the poorly known A. agglutinata (Berk. & M. A. Curtis) Lloyd which is separated by its more elongate spores. It''s quite possible that the extensively cracked surface of the cap in the type was an accident due to environmental factors. Unfortunately presence or absence of clamps in the fruiting body could not be determined by Jenkins due to the condition of the type. The colors of the fruiting body are unknown.—R. E. Tulloss
(Berk. & M. A. Curtis) Sacc. 1887. Syll. Fung. 5: 18.
"Little Mountains Amanita"
≡Agaricus monticulosus Berk. & M. A. Curtis 1853. Ann. Mag. Nat. Hist., Ser. 2 12: 418.
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, (Bas 1969), and (Jenkins 1977).
Note: Jenkins used the term "gloeoplerous hyphae" instead of "oleiferous hyphae" (Bas 1969, 1978, etc.) or "vascular hyphae" (the usage of the editors of this site).
type study of Jenkins (1977): ca. 55 mm wide, convex to plano-convex, possibly with slight umbo, areolate; context not described; margin not striate; universal veil as angular or pyramidal warts (one in each areola, when pileus areolate), towards margin becoming more flocculent.
type study of Jenkins (1977): ca. 50 × 4 - 9 mm, tapering slighty upward; bulb subclavate to clavate; context not described; partial veil not described; universal veil "fibrillose to fibrillose-scaly with subfloccose patches on margin of bulb."
Jenkins (1977): filamentous hyphae densely interwoven to subradially arranged, gelatinized [at least in part?—ed.].
Jenkins (1977): 42 - 47 × 4.5 - 11 μm, usually 4-sterigmate; clamps not observed.
Jenkins (1977): On pileus: filamentous hyphae 2 - 10 μm wide, "mostly gloeoplerous," moderately branched; clamps not observed; inflated cells up to 80 × 35 μm, subglobose to ellipsoid to clavate to elongate, "usually" in short terminal anticlinally arranged chains, with "some" larger elongate cells "being" terminal. On stipe base: filamentous hyphae moderately branched, "mostly gloeoplerous"; inflated cells globose to subglobose to broadly ellipsoid to elongate, "usually" in terminal chains with broadest cells" usually" terminal.
Jenkins (1977): [-/1/1] 9.8 - 11.2 × 7.0 - 8.0 (-9.0) μm, (Q = 1.19 - 1.50; Q = 1.35), hyaline, smooth, thin-walled, inamyloid, broadly ellipsoid to ellipsoid, adaxially flattened; apiculus sublateral, truncate-conic; contents guttulate; color in deposit not recorded.
Jenkins (1977): U.S.A.: SOUTH CAROLINA—unkn. loc., ix-xi Curtis 2853 (lectotype, K, sheet II packet II right basidiome).
Bas (1969): "In a few American herbaria I found collections under this name that appeared to belong to species of Amanita section Lepidella. This is probably because Singer (1948: 35) once applied this name to the species now called A. cokeri, earlier described under the name 'A. solitaria Bull.' by Coker (1917: 68) with the name 'A. monticulosa B. & C.' as synonym. After an examination of the type collection, which appeared to have non-amyloid spores, Singer (1955: 399) changed his mind.
"A check of this character of the type showed that Singer's statement to be correct. Amanita monticulosa represents one of the taxa belonging to the A. gemmata-group, which in North America is particularly polymorphous and confusing."
Jenkins (1977): "In the original description not type was designated, but two specimens were cited. These syntypes are contained in three packets on one herbarium sheet at K. Collection no. 2879 is in one packet and no. 2853 is in two packets. The primary character used for the determination was presence of pyramidal warts. Thus the apico-basal arrangement of the chains of inflated cells in the volval remnants on the pileus separated the specimens on sheet II from those on sheets I and III. Also the specimen on sheet I had no spores. On sheet II the left-hand specimen is probably the same as the right-hand specimen, but because of its immaturity this is difficult to confirm. Therefore, the right-hand specimen on sheet II seems to be the best choice as lectotype. This is in agreement with Bas (annotated specimen)."
—R. E. Tulloss
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Each spore data set is intended to comprise a set of measurements from a single specimen made by a single observer;
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Combining more data into a single data set is non-optimal because it obscures observer differences
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a single collection inadvertently contains a mixture of taxa.