Irpex lacteus (Fr.) Fr. 1828

Irpiciporus lacteus (Fries) Murrill
Sistotrema lacteum Fries, Obs. Myc. 2: 266. pi. 6,f. 1. 1818.
Boletus Ttilipiferae Schw. Schr. Nat. Ges. Leipzig 1 : 99. 1822. (Type from North Carolina.) Irpex sinuosus Fries, Elench. Fung. 1 : 145. 1828. (Type from Sweden, on fallen oak branches.) Irpex pallescens Fries, Epicr. Myc. 522. 1838. (Type from North America, on trunks of Lirio-
dendron.') Irpex Tulipiferae Fries, Epicr. Myc. 523. 1838. Irpiciporus Tulipiferae Murrill, Bull. Torrey Club 32 : 472. 1905.
^ The spore-characters of many of the species treated in the following pages have been obtained for me by Mr. Guy West "Wilson. It has been impossible to examine the spores in many of the older type specimens, and in some specimens spores could not be found. Pileus extensively effused, shortly reflexed, imbricate, sessile, dimidiate, laterally connate, 0-1.5X1^X0.1-0.2 cm.; surface white, subzonate, concentrically furrowed in large sf)ecimens, villose ; margin very thin, defiexed, undulate to lobed : context white, membranous, less than 1 mm. thick ; tubes short, irregular, white to isabelline, 1-3 mm, long, mouths angular, about 2 to a mm., edges uneven, soon splitting into teeth, which are compressed, pointed, fimbriate, dentate to incised: spores cylindrical, slightly curved, smooth, h3^aline, 6-7 X 2-3 fJ; hyphae septate, 2-3 ^i ; basidia 16-20 /i.
Type locality : Sweden.
Habitat: Dead deciduous wood.
Distribution : North America ; also in Burope and Asia.