Blue Cheese Polypore

Foodplant / saprobe
fruitbody of Postia caesia is saprobic on dead wood of Pinus
Other: major host/prey

Foodplant / saprobe
fruitbody of Postia caesia is saprobic on dead wood of Larix
Other: minor host/prey

Foodplant / saprobe
fruitbody of Postia caesia is saprobic on dead wood of Picea
Other: minor host/prey

Foodplant / saprobe
fruitbody of Postia caesia is saprobic on wood (worked) of Pinopsida
Other: unusual host/prey

In Great Britain and/or Ireland:
Fungus / parasite
internal basidiome of Tremella polyporina parasitises live hymenium of basidiome of Postia caesia

Tyromyces caesius (Schrad.) Murrill
Boletus caesius Schrad. Spic. Fl. Germ. 167. 1794. Boletus albidus Sow. PJngl. Fungi pi. 226. 1799. Polyporus caesius Fries, Syst. Myc. 1 : 56. 1821.
Pileus dimidiate, sessile, imbricate, often narrowly attached, with a prominent umbo, variable in habit and size, fleshy-tough, soft, spongy when fresh, fragile when dry, 1-2 X 3-6 X 0.5-1.5 cm. ; surface sodden, tomentose or villose-tomentose, azonate,, murinous or griseous when fresh, becoming caesious or fading to nearly pure-white on drying, often nearly glabrous with age: context white, homogeneous, soft, friable, 5-8 mm. thick; tubes long and slender, 5-10 mm. long, caesious within, collapsing, friable, mouths angular, 3-4 to a mm., edges white or bluish-gray, very thin, dentate to long and sharply lacerate: spores elongate, smooth, hyaline, 5-5.5 Y, 1.5 ft.
Type locality : Germany.
Habitat : Dead deciduous and coniferous wood. Distribution: Canada to Tennessee ; also in Burope.