 Description： |
Pileus 3.5-6 cm broad, convex becoming nearly flat or irregular in age; color dark smoky drab to brownish gray, often with a flesh colored tint, surface dry, distinctly velutinous then glabrous, with at first incurved then narrowly projecting sterile margin. Context white to creamy gray, changing to pinkish or purplish brown when bruised, eventually becoming blackish. Stipe 4-9 cm long, 6-13 mm thick, clavate becoming equal, concolorous with the pileus but paler at the apex when young, pruinose to velvety, lackening when rubbed, usually heavy and often irregular, or slightly tapering upwards, rarely tapering downwards, solid, context pale grayish and changing to reddish and then black when bruised, basal mycelium sordid white. Tubes 4-8 mm long, white to pale gray, later flesh colored, when injured changing slowly to black or reached blackish through pink or purplish brown, adnate to depressed with decurrent lines; pores somewhat variable in shape and folded together, later mostly rounded-angular, about 2 per mm , concolorous with the tubes and changing as tubes when bruised. Spore print vinaceous to brownish-flesh color; spores 11-15.5 × 3.5-4 μm, obclavate or oblong to fusoid, pale brownish melleous in KOH, pale dingy yellow-brown to dull rusty brown in Melzer, s reagent, smooth, wall scarcely thickened, narrowly ovate in face view, somewhat inequilateral in profile. Basida 23-34 × 9-12 μm, 4-spored, sterigmata 4-5 μm long, clavate, yellowish to pale brownish in KOH. Pleurocys-tidia 45-73 × 13-15 μm, fusoid-ventricose, thin-walled, smooth, content pale bister in KOH, darker bister in Melzer,s reagent. Cheilocystidia little differentiated but smaller. Many hy-phae in the tube trama of the Boletus type with dark granules in KOH or in Melzer,s reagent but inamyloid. Epicutis of the pileus made up of a palisade of hair-like hyphae which are dark fuscous, slightly attenuated upwards, but obtuse at the tip, rarely subacute, brittle, wall 0.5-0.9 μm thick, densely arranged, 4-7.5(12) μm broad. Similar hairs also found on the covering layer of the stipe. The palisadic structure eventually disorganized and approached a trichodermium. |
| Specimens： |
Taiwan, Nantou: Hui-Sun Forest Experimental Station, alt.1850m, 1 Aug. 2000, Chen CM. 2428. Taichung: Chingjing, alt.1900m, 7 Jun 2001, Chen CM. 2845. |
| Distribution： |
Taiwan, Japan, North America, China (Sichuan, Yunnan, Guangdong, Guangxi, Fujian, Anhwei). |
| Note： |
Singer (1974) established the species Tylopilus nigricans Singer, including different forms with differences in shapes of cystidia and sizes of spores and carpophores. Corner (1972) still treated these forms as the species Tylopilus alboater. In spite of its color and dark flesh, this species is not readily distinguishable in the field, and apparently has different forms of varieties required for further study (Smith and Thiers 1971). For an example, the short tubes and externally compact and hard stipes, T. alboator was once placed under the genus Gyroporus, which is characterized by elliptical spores and white or citrine when it is in mass. Also, paler specimens of T. alboator are often confused with T. ferrugineus, but the former has a bister content of cystidia in KOH, whereas the content of the latter is yellow. |
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Phylum：Basidiomycota >> Class： Basidiomycetes >> Order： Boletales