30 THE GASTEROMYCETES OF THE UNITED STATES AND CANADA 



have a texture only slightly harder and firmer than a raisin; many plants of No. 6003, 

 however, are bony hard when dry. The above mentioned plants agree in all characters 

 except the ones mentioned above, and we are therefore retaining numbers 7450, etc., 

 under R. rubescens as a color form. 



North Carolina. Chapel Hill. Nos. 58, 1444, 1932, 6003, 6043, 6049, 7199, 7203, 7204, 7212, 7213, 

 7218, 7223, 7450, 7457, 7499, 7563, 7564, 7565, 7567, 7570, 7573, 7579, 7583. 



Saxapahaw. Coker, coll. August 1922. No. 5503. On ground under cedars. Strongly parasi- 

 tized internally by a mold with large, spherical, spiny, golden yellow spores, 18-22jk 

 thick. These spores were so abundant as to give their color to the entire gleba, but the 

 spores of the host had also matured and were like those of our collections. There were 

 no external signs of a parasite, the surface being to all appearances normal. 



Asheville. Beardslee, coll. 



South Carolina. Sandy soil in pine and oak woods, just under loose surface leaves, about 7 miles above 



Georgetown, Dec. 29, 1926. Coker, coll. (U. N. C. Herb.) . Spores 2.-2.8 x 6-8.5,*. 

 Alabama. Auburn. Earle, coll. (Path, and Myc. Herb., as R. grazcolens). 



Rhizopogon nigrescens n. sp. 



Plates 23 and 107 



Fruiting body above ground, about 2-6 cm. wide by 1.5-3 cm. high, subglobose, 

 pure white when young and fresh, becoming mottled with several colors when maturing, 

 about light cadmium (Ridgway) beneath, shading to russet on top, turning orange 

 below or reddish brown above when rubbed and later almost black; becoming chestnut 

 to bay or inky black upon drying; fibrils numerous but slender, quite conspicuous in 

 fresh plants, innate-appressed above, becoming more conspicuous below, passing into 

 several rhizomorphous strands, reddish when fresh, becoming concolorous with the 

 peridium and so inherently appressed above and on the sides on drying as to be quite 

 inconspicuous, usually remaining free and conspicuous below. Fresh peridium slightly 

 sticky, about 290-400yu thick, simple, filled with a bright red or orange amorphous 

 material which gives a strong color to a section and which seems to cause the surface 

 color when rubbed; color changing slowly to a deep purple upon the application of 

 7% KOH ; in old specimens in which deliquescence has proceeded far the peridium may 

 be very thin or even absent in places; threads of peridium septate, only slightly branched 

 1.%-Aij. thick. Gleba pure white when fresh, turning light clay color, sometimes with a 

 tint of olive on drying; cavities labyrinthiform, up to 0.5 mm. long, not filled with 

 spores; septa 80-llOju thick (fresh) but varying much in the same collections and some- 

 time even in the same plant, only slightly if at all scissile. 



Spores 2.4-3 x 6-9/i, smooth, long-elliptic, 2-guttulate, 4—8 on each basidium, and 

 usually remaining attached even after the basidium has collapsed. Hymenium 22-30^ 

 thick; basidia 5-7.4 x 28— 38p, with thin, non-gelatinized walls; basicna extending out 

 considerably beyond the hymenial surface, collapsing more or less completely after the 

 spores are formed. In the hymenium are numerous more or less cylindrical cells which 

 along with the tramal threads become very much gelatinized as the plant deliquesces. 

 Sterigmata very short and inconspicuous. 



Plant nearly odorless when fresh, deliquescing plants fragrant, the odor faintly 

 suggesting wine or candy; the quality of the odor the same but diminishing in strength 

 on drying. 



In fresh condition the distinctive characteristics of the plants are the peridial colors 

 and the abundant slender fibrils. In the dried condition the peridium becomes very 



