Search on : Taxa descriptions


Page number:412 
Remarks (public):The circular depressions on the pilear surface, the thin, occasionally substipitate basidiocarps, and the bitter taste are good field characteristics for O. guttulatus. Conidia develop in abundance in cultures of O. guttulatus, and Davidson et al. (1946) suggested that Ptychogaster rubescens Boud. may be the imperfect stage. However, Stalpers (1978) states that P. rubescens is the imperfect stage of Punctularia atropurpurascens (Berk. & Broome) Petch. 
Description type:Non-original description 
Description:Oligoporus guttulatus (Peck) Gilbertson & Ryvarden - Mycotaxon 22:365, 1985. - Polyporus guttulatus Peck in Sacc., Syll. Fung. 6:106, 1888.
Basidiocarps annual, sessile, effused-reflexed or laterally substipitate; pilei solitary or imbricate, dimidiate to flabelliform, applanate, up to 9 x 10 x 2 cm; upper surface white when fresh, drying buff or pale brown, azonate or faintly zonate, glabrous, smooth, pelliculose, often with small, shallow, circular depressions 1-3 mm in diam; margin concolourous; pore surface white to cream coloured, drying pale buff, the pores circular to angular, 4-6 per mm, with thin dissepiments that become lacerate with age; context white to cream coloured, azonate, firm-fibrous, up to 1.5 cm thick; tube layer with a pale greenish tint in fresh specimens, drying cream coloured, continuous and concolourous with the context, up to 5 mm thick; taste bitter.
Hyphal system monomitic; contextual hyphae with clamps, some extremely thick-walled with a narrow, capillary lumen, not staining in phloxine, occasionally nodose-septate, commonly branching opposite the clamp, 4-8(-12) µm in diam; some with thin to partially thickened walls, with abundant clamps and occasional branching, not staining in phloxine, 3-6 µm in diam; gloeoplerous hyphae also present, staining bright red in phloxine, thin-walled, with occasional distorted clamps, sinuous and with constrictions
and swellings, 5-10 (-14) µm in diam; tramal hyphae mostly of the thin-walled, non-staining type.
Cystidia absent; cystidioles fusoid, not projecting beyond basidia, 13-18 x 4-5 µm, with a basal clamp.
Basidia clavate, 4-sterigmate, 15-20 x 5-6 µm, with a basal clamp.
Basidiospores short-cylindric to oblong, hyaline, smooth, negative in Melzer's reagent, 4-5 x 2-2.5 µm.
Type of rot. - Brown cubical rot of dead conifers and hardwoods, also a brown butt rot of living Picea .
Cultural characteristics. Davidson et al 1946; Nobles 1948, 1958, 1965; Stalpers 1978, David 1980.
Sexuality. Unknown.
Substrata. On dead conifer wood and in Europe noted mainly on Picea, very rarely on
Distribution. Seemingly a typical eastern immigrant and more or less restricted to the natural area of Picea in Europe. Circumpolar in the boreal conifer zone.
Taxon name: