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Page number:93 
Description type:Non-original description 
Description:ALEUROCYSTIS G. Cunn. Trans. Roy. Soc. New Zeal. 84: 234, 1956.
Basidiocarp cupulate to resupinate, pale yellow to ochre, annual, gelatinous and tough when fresh, horny and dense when dry, hyphal system monomitic, generative hyphae with clamps, thick-walled in the subiculum and straight to branched, gelatinized in KOH, basidia clavate with 4 sterigmata, metuloid cystidia present, thick-walled, encrusted at least in the upper part, in age also in lower part and more elongated, projecting to enclosed in old basidial layers, paraphysoid hyphae in some cases coming close to dendrohyphidia present in the hymenium, unbranched to slight branched, basidiospores smooth, large, thin-walled and non-amyloid, on dead hardwoods, two species, one pantropical, the other tropical America.
Type species: Aleurodiscus capensis Lloyd.
Remarks: The genus is probably not related to Aleurodiscus, but specimens are frequently collected and determined as belonging to that genus because of the discoid, scutellate basidiocarp with large basidiospores. The non-amyloid basidiospores and the metuloids will however, immediately exclude it from Aleurodiscus where such characters are unknown.
It may be that the genus is related to Cytidia and similar genera with which it shares the same type of semigelatinous cupulate basidiocarps and large basidiospores even if this of course may be a result of convergence. It is well known that basidiomycetes that produce basidiocarps in exposed environments as still attached dry branches, have large basidiospores (Ryvarden, 1991). The reason for this is unknown, but as the phenomena occur in several distant groups, it must have an adaptive value. The metuloid cystidia in Aleurocystis will however separate the genus from Cytidia Quel. and Auriculariopsis (Lev.) Maire species of which are rather similar to Aleurocystis species in the field.
Whether such metuloid cystidia indicate a different origin from that of the other genera, is debatable as there are many corticoid genera where such organs occur without being taken into account in the definition of the genus. Good examples are Gloeocystidiellum Donk, Hyphoderma Wallroth, Peniophora Cooke and Phlebia Fr. In these genera presence or absence of thick-walled metuloid cystidia are only used as a practical and pragmatic tool for separation of species.
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