Amanita umbrinelloides - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita umbrinelloides
name status nomen acceptum
author A. E. Wood
english name "False Umber Amanita"
intro

The description is largely based on the original description (Wood 1997).

cap The cap of Amanita umbrinelloides is up to 90 mm wide, convex then flattened, finally with the margin flaring up, smooth, dry, vaguely appearing to have radiating hairs imbedded in cap surface, not striate, mouse-gray to dull gray, sometimes with pallid brown shades, with volval remains as scattered, flat patches, felted to membranous, white to off-white to pale gray, paler than the cap.
gills Gills are thin, crowded, white to pale gray, with a concolorous margin.  The short gills are present in at least one or two series.
stem The stem is 110 × 10 mm, equal to slightly enlarged below, more or less smooth to finely fibrillose, white to cream-gray.  The ring is flared, membranous, persistent, but sometimes fragile, slightly striate above, and white to gray.  The bulb appears to be indistinct in Wood''s material.  The base is equal to slightly enlarged and white to pale cream.  The volva is present on the bulb as a small but distinct free limb that is membranous and persistent and gray, sometimes reduced, and (in one case) absent [Wood's illustration shows neither bulb nor volva at base of stem].
spores The spores measure (9.0-) 11.4 - 15.0 × (8.4-) 9.9 - 12.6 µm and are subglobose and inamyloid.  Clamps are easily seen at bases of basidia.
discussion

Wood describes this species from both subalpine woodland and sclerophyll woodland.  Subalpine woodland in New South Wales (Australia) includes such tree genera as Acacia, Eucalyptus, Kunzea, Leptospermum, and possibly others (for example, see this sample report on subalpine vegetation in NSW).  A sclerophyll forest in the Australian bush is a forest of hard-leaved plants including Eucalyptus in the overstory (wikipedia).

The shades of brown and gray in the cap, the membranous grayish limb of the volva, the easily distinguishable clamps on the basidia, large spore size, a ring that sometimes is lost, all strongly suggest a group of species related to Amanita merxmuelleri Bresinsky & Garrido described from Nothofagus forests in Argentina and Chile, South America.  Further examination of the potential relationship could be very helpful in understanding the dispersal of formerly Gondwanan mycota.—R. E. Tulloss and L. Possiel

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