Australasian sequestrate (truffle-like) fungi. XII. Amarrendia gen. nov.: an astipitate, sequestrate relative of Torrendia and Amanita (Amanitaceae) from Australia

Abstract

Five species of Amarrendia gen. nov. (Amanitaceae) are presented, three new species A. oleosa, A. nemoribus and A. peridiocrystalia and two new combinations A. grandispora and A. lignicolor formerly placed in Alpova. It is proposed that Amarrendia occupies a systematic position within a complex of related taxa that also incorporates Torrendia and Amanita. Basidiomes of Amarrendia resemble those of the genus Torrendia, except for the absence of a stipe. Characteristics of Amarrendia that closely resemble those of Torrendia include (i) white or cream peridium and the similarly coloured, loculate gleba which may be empty or filled with a rapidly drying clear liquid, (ii) fragile consistency of the basidiome flesh in some species, (iii) glistening, minutely granular surface of the basidiomes (because of inflated cells exposed at the surface), (iv) broad ellipsoid, smooth, thin-walled, hyaline, non-amyloid, non-dextrinoid spores with a large oil droplet and a broad tapering apiculus and (v) context trama composed of inflated and hyphal elements intermixed. Amarrendia is currently known only in temperate Australia where it occurs in natural ecosystems and plantations in association with ectomycorrhizal plants such as Eucalyptus, Allocasuarina and Gastrolobium.