Amanita aurantiovelata - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita aurantiovelata
name status nomen acceptum
author Schalkw. & G. M. Jansen
english name "Chilean Orange Dust Amanita"
images

  • 1. Amanita aurantiovelata, Cuinco, Los Lagos, Chile


  • 2. Amanita aurantiovelata, from Southern Beech (Nothofagus) forest, Andean Chile.



  • 3. Amanita aurantiovelata, from Southern Beech (Nothofagus) forest, Andean Chile.


  • 4. Amanita aurantiovelata, from Southern Beech (Nothofagus) forest, Andean Chile.

    • cap The cap of Amanita aurantiovelata is up to 45 mm wide, semiglobose when young, convex when older, with umbo, deep orange to red-orange when young, fading to orange or orange yellow and pale yellow later, at first felted and mat, later smooth and shiny, with a sulcate-striate margin. The volval remnants are fragile, deep orange, in slenderly conic warts with pallescent tips in the beginning, then later glabrous.
    gills Gills are free, moderately crowded, white to whitish, and often have a frimbriate edge, especially near the stem.  Short gills are scarce.
    stem Its stem is up to 75 × 10 - 12 mm, clavate when young to almost cylindrical with approximately pointed bulbous base with age, solid, exannulate, white to pale yellow, somewhat pulverulent, with deep orange, floccose volval remnants at the base and on the top of the stem''s bulb.
    spores The spores of this species measure (8.8-) 9.0 - 12.0 (-12.6) × (6.0-) 6.4 - 7.6 (-9.0) µm, and are broadly ellipsoid to ellipsoid and inamyloid. Clamps are present at bases of basidia.
    discussion

    Amanita auranitovelata was originally described from Chile in association with Nothofagus.  It is locally quite common in the coastal and Andean cordilleras as well as in the valley between the ranges.

    Amanita aurantiovelata is probably of Gondwanan origin.  Amanita xanthocephala (Berk.) D. A. Reid & Hilton of Australia appears rather similar macroscopically, but lacks clamps on basidia and has much more nearly rounded spores.  The group of brightly colored taxa with powdery volvas (brightly pigmented, but fading in sunlight) having clamped basidia is very small and possibly comprises only distantly related, relict taxa.  They are distinctly segregated from the clampless or nearly clampless taxa with exannulate stem and powdery volva in the "groups" related to A. farinosa Schwein. and A. xanthocephala.  A brightly colored species with at least occasional basidial clamps is A. parcivolvata (Peck) E.-J. Gilbert; however, the relationship between the volva and the cap's skin in that species is closer to that of A. muscaria (distinct, separate, crumb-like warts on a cap skin that gelatinizes early in development) than it is to the present species, which retains a powdery smear of volva on the cap past maturity.  Consequently, given our current understanding, A. aurantiovelata is rather isolated morphologically.  The reader may also wish to see the page on Amanita calochroa Simmons et al.—R. E. Tulloss

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