1. Amanita exitialis, type locality, Guangzhou [sub-provincial] City - Guangdong, China.
2. Amanita exitialis, type locality, Guangzhou [sub-provincial] City - Guangdong, China.
The fruiting body of Amanita exitialis
is small to medium-sized. The cap is 40 - 70 mm wide,
convex to applanate, sometimes slightly depressed at
center, glabrous, white, and sometimes cream-colored over
disc. Its margin is nonstriate and nonappendiculate, and the flesh is white.
The gills are free, white to whitish, and crowded; the short gills are attenuate,
plentiful, and in 2 - 3 ranks.
The stem is 70 - 90 × 5 - 10 mm, white to whitish, glabrous, or sometimes with fibrillose
squamules, and subcylindric or slightly tapering upward.
The apex is slightly expanded, and the flesh is white.
The stem's basal bulb is subglobose and 10 - 20 mm wide.
The volva is on the bulb as a short, membranous limb. It
is thin and membranous, and the free limb is up to 7 mm
high, inner and outer surfaces of the limb are white. The
annulus is apical to subapical, thin, membranous, white,
skirt-like, and often persistent (although it may be torn
from stem during expansion of cap).
All parts of A. exitialis become yellow when wetted with dilute KOH solution.
This species is deadly POISONOUS.
The spores measure (9.0-) 9.5 - 12.0 (-14.5) × (8.5-) 9.0 - 11.5 (-13.0) µm and
are globose to subglobose (rarely broadly ellipsoid) and
amyloid. Clamps are absent from the bases of basidia.
Unlike most other agarics, the basidia of this species
are almost entirely 2-spored (rarely 1-spored).
This mushroom grows in broad-leaved
forest. One woody plant with which it is proposed to be symbiotic is Castanopsis
fissa (Zhang et al., 2005).
The present species was described from southern
China where it is known only from Guangdong Province.
The present species is deadly POISONOUS.
In mid-March of 2000, a disaster happened in Guangzhou [sub-provincial] City - southern China (Guangdong Prov.)
due to eating this mushroom. Nine persons ate the mushroom, only one of them survived.
Zhang et al. (2004), Key Lab. Biodivers. Biogeogr., Kunming Inst. Bot., Yunnan, China
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.
NOTE: Spore measurements from papers by Z. L. Yang use his "Times New Roman" face for "Q"
and "Q'"—respectively, "Q" and "Q."
It is interesting to consider comparison of the spores of the present species with the spores of the most similar white species of sect. Phalloideae that produce a yellow reaction to a macrochemical spot test with KOH solution.
First, here is the sporograph comparison with A. bisporigera.
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.