Name: Antrodiella canadensis
Author: (Overh.) Niemelä
Citation: in Niemelä, Kinnunen, Larsson Schige & Larsson, Karstenia 45(2): 75 (2005)
Deprecated Synonyms: Antrodiella overholtsii Ryvarden & Gilb., Polyporus canadensis Overh., Polyporus canadensis Overh. ex J. Lowe, Tyromyces canadensis (Overh. ex J. Lowe) J. Lowe, Flaviporus overholtsii (Ryvarden & Gilb.) Ginns, Leptoporellus canadensis (Overh. ex J. Lowe) Spirin
Collected by : J. W. Groves
Collectors number : Overbolts 16860
Collection date : 16/08/1933
Country (state) :
Location details : Dow’s Swamp, near Ottawa
Host : Picea
Substrate details : stump,
Status : Holotype
Ryvarden, L.; Gilbertson, R.L. 1993. European polypores. Part 1. Synopsis Fungorum. 6:1-387
Page number : 160
Remarks (public) : Macroscopically like an Oligoporus species, but much denser and with far smaller spores than species in this genus. The resinous lines in the context and the smaller spores of A. overholtsii separate it from specimens of A. semisupina.
Description type : Non-original description
Description : Antrodiella overholtsii Ryv. & Gilbn. – Mycotaxon 18:138, 1984. – Polyporus canadensis Overh., Mycologia 33:97. 1941 (invalidly published, see Ryv. & Gilbn. op.cit.).
Basidiocarps annual, pileate, sessile to slightly fanshaped with contracted base, often imbricate, up to 6 cm wide and long, 4-8 mm thick at the base, soft and tough when fresh, hard and dense when dry, taste sweet; upper surface first white, soon more sordid brown to grayish, tomentose to velutinate, with age becoming more strigose and with radial lines of agglutinated hyphae or small warts, margin sharp and bent down in dry specimens; pore surface at first white, then cream to straw-coloured or sordid brownochraceous, slightly shiny and semitranslucent as if partly soaked by some resinous substance in old specimens; pores angular and thin-walled, 5-6 per mm; context at first white and homogeneous, with age more dense and pale straw-coloured, with dark lines or zones of some dark substance; tube layer fragile, straw-coloured and resinous-dense, darker than the context.
Hyphal system dimitic; generative hyphae predominant in the context, thin- to thick-walled, 3-5 µm in diam; the same type present in the trama, but there mixed with agglutinated skeletal hyphae, these thick-walled to solid. 2-5 µm in diam.
Cystidia none, but fusoid. non-projecting cystidioles scattered among the basidia, 18-20 × 5-6 µm.
Basidia clavate. 4-sterigmate, 18-20 × 4-6 dun, with a basal clamp.
Basidiospores ellipsoid to ovoid, or subglobose to almost pear-shaped. hyaline, smooth. negative in Melzer’s reagent. 2.5-3 × 2-2.5 µm.
Type of rot. Causes a stringy white rot of dead conifers.
Cultural characteristics. Unknown.
Substrata. On dead gymnosperms. reported only from Picea and Pinus. Distribution. In Europe known only from Northern Finland (Niemel? 1985) and Germany (Schmid Heckel 1985). In North America known from the northern spruce forests.
Polyporus canadensis MYCOL 33:97. 1941. Illegitimate name, no Latin description. Type: Canada, Ontario, Ottawa, Davis Swamp, Aug. 16, 1933, J. W. Groves. Overholts no. 16860.
Lowe (1975:44) accepted the taxon in Tyromyces and was aware that a Latin diagnosis or description was lacking. Thus, he supplied one, but very unfortunately he described the taxon in Polyporus and at the same time made the combination in Tyromyces. By doing this, he contravened Article 34 in the ICBN and both the name and the combination are invalid. We accept the species, but feel it should better be placed in Antrodiella because of its dimitic hyphal system and very small ellipsoid to oval spores. In changing the name we would like to honour Overholts and propose: Antrodiella overholtsii Ryv. & Gilbn., sp. nov. There is a detailed description in Lowe (op. cit.). http://www.mycobank.org/...
Description : Polyporus canadensis sp. nov. (Figs. 7, 11)
Sporophore imbricate-sessile with a tendency to be substipitate by a narrowed base, watery-tough when fresh, drying rigid and brittle, the cluster 6 × 10 × 5 cm., composed of about 6 partially confluent pilei ; pileus 3-5 × 3-7 × 0.3-0.8 cm., white or waterywhite when fresh, drying pallid, densely soft-tomentose with erect tomentose tufts that roughen the surface of dried specimens; context duplex, the upper softer layer consisting of the tomentose covering, white, 2-4 mm. thick, drying fragile, with a sweet odor when fresh; pore surface white, drying somewhat yellowish, the tubes 2-4 mm. long, fragile when dried, their mouths angular, very thin-walled but entire, subshining, 4 to 6 per mm.; spores very minute, subglobose or broadly ellipsoid, smooth, hyaline, 1-guttulate, 2-3 × 1.5-2 [t; cystidia as inconspicuous paraphysis-like organs slightly larger than the basidia, bluntly pointed at the tips, 4-5 µm diameter; basidia 3.5-4 µm diameter; context hyphae somewhat agglutinated, sparingly branched, thin-walled, septate, with clamps, mostly 4-6 [t diameter.
On stump of Picea. Type collected in Dow’s Swamp, near Ottawa, Canada, August 16, 1933, by J. W. Groves. Overbolts Herbarium 16860 and Herbarium of the Central Experimental Farm, Ottawa, 3593.
Superficially except for the small pores this resembles P. borealis. The very minute spores (seen attached to basidia as well as free and abundant) make this a characteristic species. The habit also recalls that of P. osseus from which it is in every other character distinct. The rough surface of the pileus recalls P. galactinus and P. immitis and these are its closest relatives. The context is not zonate as in the former species, the spores are a bit smaller, the habitat is different, and the context does not dry resinous. About the same characters separate it from P. immitis.
Created: 2014-12-09 10:20:10 CST (-0500) by walt sturgeon (Mycowalt)
Last modified: 2020-02-20 04:11:29 CST (-0500) by Erlon Bailey (Herbert Baker)
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