The fruiting bodies of Amanita yuaniana
are medium-sized to large. The cap is 70 - 130 mm wide,
convex to planate, not umbonate, grey, grey-brown, brown
to sepia, with white to whitish spots, innately
fibrillose, usually glabrous, occasionally with a few
white, membranous volval remnants; the cap margin is
short striate (up to 10%, rarely 20% of radius) and non-appendiculate; its context is white.
The gills are free to nearly free, crowded, white, with greyish edges; the short gills are truncate.
The stem is 70 - 140 × 10 - 25 mm,
subcylindrical or slightly tapering upwards, white to
greyish, glabrous or covered with white to greyish
fibrillose squamules; the context is white and fistulose;
the stipe lacks a basal bulb. At the stipe's base, the
volva is saccate, 40 - 60 × 40 - 50 mm, membranous, 1 - 3
mm thick, with both surfaces white to dirty white.
Sometimes the upper part of the outer surface is greyish.
The volva has a white to greyish internal limb. The
species has a superior annulus that is membranous; its
upper surface is white to greyish, with fine radial
striations; its lower surface is grayish and fibrillose.
The spores measure (8.5-) 9.5 - 12.0 (-13.0) × (6.0-) 6.5 - 8.0 (-9.5) µm and are
ellipsoid and inamyloid. Clamps are common at the bases of basidia.
Amanita yuaniana is edible
and can be found in free markets during rainy seasons.
This species was originally described from Sichuan Province, China, and is common in
southwestern parts of the country.—Zhu L. Yang
Note: The species is assignable to stirps Hemibapha. - RET
Zhu L. Yang. 1994. Mycotaxon 51: 464, fig. 8 (1-5).
Zhang et al. (2004), Key Lab. Biodivers. Biogeogr., Kunming Inst. Bot., Yunnan, China
Z. L. Yang. 1997. Biblioth. Mycol. 170: 60, figs. 44-47.
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).
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this text is appropriate.
Olive text indicates a specimen that has not been
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where data is missing or uncertain.
The following material is based upon the protolog and the revision of Yang (1997) unless otherwise indicated.
NOTE: Spore measurements from papers by Z. L. Yang use his "Times New Roman" face symbols for "Q" and "Q'"—respectively, "Q" and "Q.
from protolog: [90/3/2] (8.0-) 9.0 - 11.0 (-12.5) × (6.0-) 7.0 - 8.0 (-8.7) μm, (L = 10.1 - 10.3 μm; L' = 10.2 μm; W = 7.3 - 7.5 μm; W' = 7.4 μm; Q = (1.15-) 1.33 - 1.46 (-1.57); Q = 1.36 - 1.38; Q' = 1.37), hyaline, colorless, smooth, thin-walled, amyloid [later determined to be inamyloid (Yang 1997)—ed.], ellipsoid, rarely broadly ellipsoid; color in deposit not known.
from Yang (1997): [390/13/11] (8.5-) 9.5 - 12.0 (-13.0) × (6.0-) 6.5 - 8.0 (-9.5) μm, (Q = (1.27-) 1.31 - 1.61 (-1.74); Q = 1.45 ± 0.09), ellipsoid, rarely broadly ellipsoid or elongate, inamyloid, colorless, hyaline, smooth, thin-walled; apiculus up to 1.0 μm long.
from protolog: At 2,000 - 2,200 m elev. In forest dominated by Pinus yunnanensis mixed with some trees of the Fagaceae or in pure P. yunnanensis forest.
from Yang (1997): Solitary or in small groups. At 2000 - 2900 m elev. In Coniferous and mixed forests with Pinus (e.g., P. yunnanensis and P. armandii) and Quercus species.
from protolog: CHINA: SICHUAN—Liangshan Yi Autonomous Prefecture - Puge Co., unkn. loc., 25.vii.1992 P. Q. Sun 1950 (paratype, HKAS 25758). Panzhihua Prefecture - Miyi Co., unkn. loc., 27.vii.1986 M. S. Yuan 1187 (holotype, HKAS 18383).
from Yang (1997): CHINA: SICHUAN—Liangshan Yi Autonomous Prefecture - Puge Co., unkn. loc., 2200 m elev., 25.vii.1992 P. Q. Sun 1950 (HKAS 25758); Xichang (county level) City, Luojishan, 1800 m elev., 22.vii.1992 P. Q. Sun 1888 (HKAS 25779); Xichang (county level) City, Luojishan, 2000 m elev., 19.vii.1983 M. S. Yuan 35 (HKAS 11829), 270 (HKAS 12006). Panshihua (prefecture level) City - Miyi Co., Puwei, 2000 m elev., 27.vii.1986 M. S. Yuan 1187 (HKAS 18383).
YUNNAN—Dali Bai Autonomous Prefecture - Binchuan Co., Jizushan, 2900 m elev., 10.viii.1985 G. P. Xiao 562 (HKAS 17270). Lijiang (prefecture level) City - Yulong Nakhi Autonomous County, Xiangshan, 2500 m elev., 27.vii.1985 M. Zang 10002 (HKAS 14869 & 14870); Yulong Nakhi Autonomous County, Xiangshan, 1.viii.1985 M. Zang 10187 (HKAS 15089); Yulong Nakhi Autonomous County, Yulongshan, 30.vii.1986 R. H. Petersen 56376 (HKAS 20103), 31.vii.1995 Z. L. Yang 2103 (HKAS 29516).
RET: CHINA: YUNNAN—Lijiang, 1.viii.1996 David Arora s.n. (RET 257-8).
—R. E. Tulloss
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