[Vol. 2 



692 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



brown color of the hyphae in P. adustus. In the hyphae of the 

 latter species the color is brown, whether the sections are thick 

 or thin. This test will usually apply to cross-sections of the 

 tubes as well as to longitudinal sections, except that when the 

 hymenium of a growing specimen is bruised, dried, and then 

 sectioned, the mouths of the tubes and the hyphae at the ends 

 of the tubes often show a brownish discoloration that may be 

 confusing. P. crispus and P. Burtii usually are easily dis- 

 tinguished without this test, but the results are even more 

 marked in the case of those two species than in P. adustus. 



"When Peck first described P. fragrans he stated that it was 

 closely related to P. fumosas, but differed in having unequal 

 pores and an agreeable odor. In a later report he remarked 

 that it should perhaps be considered a variety of that species. 

 Microscopically the two plants are the same. There are no 

 cystidia and the spores are oblong-ellipsoid, and measure 

 4.5-6 X 2-3 ii, thus being slightly larger than the spores of 

 the three species discussed above. The spore characters 

 given for both species in the 'North American Flora' are 

 erroneous. From our present knowledge of the variability of 

 odors in the fungi 1 we are not warranted in laying much stress 

 on the fragrant odor ascribed to P. fragrans. Bresadola 2 

 discusses P. fumosus under the name P. imberbis and states 

 that the plant at times has a subanise odor. I have never 

 obtained such an odor from plants heretofore referred to that 

 species, but frequently the plants do have an odor that I would 

 not describe as pleasant. In the face of such evidence, it seems 

 reasonable to conclude that the odor alone should not separate 

 the two species in question. As to the size and regularity of 

 the pores of the two species, I find collections of P. fumosus 

 in which the younger specimens have minute pores and the 

 older ones have large and irregular pores, and collections of 

 P. fragrans with both large and small pores. I conclude, 



1 e. g., Polyporus graveolens Schw. I have collected this species several times 

 and have had growing plants under observation for three seasons and at no time 

 have I been able to obtain the slightest trace of an odor that would warrant the 

 application of "sweet knot" to that species. Similar results have been reported by 

 others. There is good authority, however, for stating that it is at times very 

 fragrant. 



3 Fung. Trid. p. 29. 



