Amanita ibotengutake - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
[print] [map]
name Amanita ibotengutake
name status nomen acceptum
author T. Oda, C. Tanaka & Tsuda
english name "Japanese Ringed-Bulb Amanita"
intro The following is based on the original description of Amanita ibotengutake (Oda et al. 2002).
cap The cap is 75-160 mm wide, hemispherical at first, then convex to plane, often eventually with an uplifted margin, brown to dark brown to yellowish or orangish brown, often darkest in the center, and smooth.  The striations on the cap margin have lengths up to 30% of the cap's radius.  The cap flesh is white and 6-8 mm thick above the stem.  The volval remnants on the cap are pallid pyramidal warts or small patches.
gills The gills of this species are free to remote, 9-15 mm broad, white to pale cream, crowded, and have a pruinose free edge.  The short gills are truncate to subtruncate in 1-6 ranks.
stem 55 - 160 × 9 - 24 mm, white to yellowish white to pale yellow, narrowing upward, and hollow to stuffed. The stem's basal bulb is 30 - 40 × 14-36 mm and globose or subglobose or broadly ellipsoid or ellipsoid or spindle-shaped.  The stem bear a median skirt-like ring that is sometimes torn away during expansion of the mushroom and may remain hanging from the cap's margin.  The volval remnants on the top of the stem's bulb make up several rather closely packed whole or broken [white or whitish] rings.
odor/taste Fresh specimens are said to have an odor similar to "resin."
spores The spore measurements are as follows: (8.0-) 8.4 - 10.8 (-12.0) × (5.6-) 6.4 - 8.0 (-10.0) μm.  The spores are broadly ellipsoid to ellipsoid (infrequently subglobose or elongate) and inamyloid.  Clamps are commonly present at bases of basidia.
discussion The authors claim the species is segregatable from A. subglobosa Zhu L. Yang by molecular means.

more t.b.d.—R. E. Tulloss
brief editors RET

[top]