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Page number:235 
Description type:Non-original description 
Description:Aleurodiscus botryosus Burt, Ann. Mo. Bot. Gard. 5: 198. 1918(Fig. 4) Acanthophysium botryosum (Burt) G. H. Cunn., Bull. New Zealand Dept. Sci. and Indust. Res. 145: 161. 1963.
Basidiocarp corticioid, in separate patches 2-4 mm in diameter, readily confluent, forming irregularly effused areas; margin determinate, adnate. Fructification 130-300 µm thick in cross section; texture pruinose-pulverulent. Hymenial surface concolorous, drying white to pale buff colored in older specimens; surface continuous to rimose upon drying. Context monomitic, poorly defined, composed of thin-walled, branched, simple-septate hyphae 2-2.5(-3.5) µm in diameter. Hyphae ascending to form a catahymenium composed of a mass of botryose acanthophyses, embedded pseudocystidia, and scattered basidial elements. Acanthophyses cylindrical to slightly swollen below, with partially thickened walls, finely branched at their apices; the branching, appearing to advantage in Melzer's, contains amyloid granulation. Hymenial elements, at first embedded (catahymenial) and obscured by the mass of botryophyses, emerge at maturity to form a hymenium of scattered basidia and pseudocystidia. Pseudocystidia (macrocystidia) variable, flexuouscylindric to broadly clavate, or fusiform with a tapering, simple to bifurcating apex. These elements measure 38-90 x (7-)12-19 u; contents yellowishrefractile in KOH, darkening in sulphobenzaldehyde. Basidia at maturity short-clavate to subclavate, with a median constriction, 38-68 x 10-12 µm; bearing (two-) four arcuate, subulate sterigmata up to 14.5 µm long and about 4.5 µm wide at base. Basidiospores obovoid to ovoid, 12-15 x (7-)8-11(-12) µm, apiculate, flattened adaxially, frequently adherent in groups of two to four, echinulate in Melzer's, amyloid.
Distribution: Ontario, Quebec; New England south to Florida, Alabama, Louisiana, California; France; New Zealand; Africa. The Mexican specimen cited by Burt (1918, p. 199) is Vararia pectinata (Burt) Rogers et jacks. Habitat: According to Burt this species is rare and occurs on the `dead stems of Rubus and Vitis' in North America. Burt, nevertheless, cites a specimen from Sharon, Massachusetts, found on Thuja occidentalis. The fungus is fairly common in Ontario on this conifer. On a worldwide basis this species apparently has a wide host range and occurs even on Pteridium stipes in New Zealand.
Discussion: The presence of botryophyses is diagnostic for this species. Cunningham (1956, p. 262) mentions that the basidiospores are smooth; however, the North American specimens which I have examined have inconspicuously roughened spores in Melzer's. The pseudocystidia of this species have unusual tapering apices and never possess apical gemmae. Nevertheless, in their origin and in the nature of their contents, these elements are clearly related to the more typical, constricted pseudocystidia found in other Aleurodiscus species.
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