name | Amanita aurantiobrunnea |
name status | nomen acceptum |
author | C. Simmons, T. Henkel & Bas |
english name | "Grandfather Death Cap" |
images | |
intro |
The description is based on the original description (2002). |
cap |
The cap of Amanita aurantiobrunnea is 30 - 70 mm wide, convex to applanate, plano-concave with age, sometimes with a low broad umbo, viscid when wet, tacky when dry, and rich orangish tan to light orange at the margin. The flesh is white. The volva is often present as inconspicuous, tiny, whitish to concolorous fragments on the outermost margin. |
gills |
The gills are free, thin, close to rather close, and white. The short gills are attenuate. |
stem |
The stem is 64 - 88 × 7 - 16 mm, slightly narrowing upwards, white with white floccose squamules when young, and becoming bare with age. The bulb is 22 × 35 mm and is enclosed by a membranous, white to pale brownish salmon limbate volva that either spreads away from the stem or collapses on it. The ring is at the top of the stem, white, and weakly membranous, often reduced to small white scales, but sometimes skirt-like, sometimes remaining as white fragments on the edge of the cap. |
spores |
The spores measure (6.2-) 6.8 - 9.4 × (5.0-) 5.5 - 7.5 (-7.9) µm and are subglobose to broadly ellipsoid to ellipsoid and amyloid. Clamps are absent at the bases of basidia. |
discussion |
This species was originally described from the Pakaraima Mountains of Guyana and is still known only from this region. It was collected in slope forests dominated by Dicymbe corymbosa on gray sands. For a comparison to the little known A. gayana (Mont.) Mont. in Gay, see the discussion of that species. In the original description, the authors state: "Amanita aurantiobrunnea has a peculiar character, that, as far as we know has not yet been described in the section Phalloideae, viz. a fin, white to colored, friable inner layer at least on the [inner surface of the free] limb of the volva that is responsible for the frequent presence of the rather inconspicuous, small, thin volval patches on the outermost margin of the pileus." The above is very fascinating discussion because it suggests that while sect. Amidella is unknown in South America, the present species may well a basal taxon of Amanita sect. Phalloideae that has retained the layered volva that leaves remnants of its inner layer on the cap and that tends to take on a pinkish or pinkish brown tint in section Amidella. Morphological reasons led Bas (1969) to believe that sect. Phalloideae may have arisen from an ancestor that could be placed in what we call today sect. Amidella. Recent molecular data suggests the same possibility.—R. E. Tulloss and L. Possiel |
brief editors | RET |
name | Amanita aurantiobrunnea | ||||||||
author | C. Simmons, T. Henkel & Bas. 2002. Persoonia 17(4): 566, fig. 1(a-g), pl. 2. | ||||||||
name status | nomen acceptum | ||||||||
english name | "Grandfather Death Cap" | ||||||||
MycoBank nos. | 374035 | ||||||||
GenBank nos. |
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holotypes | BRG; isotype, L | ||||||||
intro |
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 material. 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 species. | ||||||||
basidiospores | from protolog: [65/5/5] (6.2-) 6.8 - 9.4 × (5.0-) 5.5 - 7.5 (-7.9) μm, (Q = (1.0-) 1.10 - 1.35 (-1.45); Q = (1.10-) 1.15 - 1.35), with very thin to slightly thickened walls, amyloid, subglobose to broadly ellipsoid to ellipsoid; apiculus relatively broad and short, rounded; contents not recorded; color in deposit not recorded. | ||||||||
ecology | "Slope forest, dominated by Dicymbe corymbosa (Paluwayek), on gray sands." | ||||||||
material examined | from protolog: GUYANA: POTARO-SIPARUNI REGION—Pakaraima Mtns., Upper Ireng watershed - 1 km W of Kurutuik Falls, on adjacent ridge, 6.iv.1998 T. Henkel et al. TH6852 (paratype, BRG); ca. Sukabi R., 1-2 km upstream from confluence with Ireng R., 22.v.1998 T. Henkel et al. TH6431 (holotype, BRF; isotype, L); Sakaliu R., 1-2 km upstream from confluence with Ireng R., 25.v.1998 T. Henkel TH6445 (paratype, BRG); N-S running ridge ca. 1 km W of confluence of Ireng R. and Sukabi R., 27.v.1998 T. Henkel et al. TH6655 (paratype, BRG; paratype, L); E bank of Ireng R. 1 km downstream from Kurutuik Falls, 6.vi.1998 T. Henkel TH6898 (paratype, BRG). | ||||||||
citations | —R. E. Tulloss | ||||||||
editors | RET | ||||||||
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name | Amanita aurantiobrunnea |
bottom links | [ Keys & Checklists ] |
name | Amanita aurantiobrunnea |
bottom links | [ Keys & Checklists ] |
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.