32 THE GASTEROMYCETES OF THE UNITED STATES AND CANADA 



finding basidia in the old dried specimens. It seems probable that, since Zeller and 

 Dodge were studying dried specimens on the hymenia of which the spores are usually 

 so abundant as to render such delicate objects as sterigmata, even when present, 

 extremely hard to see, the long prongs figured and described by them (especially in 

 R. roseolus) as sterigmata are nothing more than the remains of the collapsed 

 basidia (fig. f). 



591. On bank of a brook, Oct. 18, 1912. Spores 2.2-2.8 x 6-7.5/*. 

 1011. Under cedars, Oct. 21, 1913. 



7177. On rocky ground in pine woods, Sept. 30, 1923. Spores 2.5-3.2 x 6.5-9**. 

 Also Nos. 976, 1031, 1910, 7198, 7210, 7227, 7372, 7478, 7566, 7569, 7582, 8139, 8168. 



South Carolina. About 7 miles above Georgetown, Dec. 29, 1926. Coker, coll. (U. N. C. Herb.). 



Spores 1.8-2.6 x 5-7.6/t. 

 Alabama. Spring Hill. Nov. 9, 1902. (Univ. Wis. Herb., as R.rubescens, and U. N. C. Herb.) 



Rhizopogon roseolus (Corda) Hollos 



Plates 24 and 107 



Plant irregularly subglobose, usually flattened above, not rarely flattened laterally 

 to about kidney-shaped, 0.5-2.5 cm. thick, nearly white when young and fresh, turning 

 reddish or purplish red (nearly Hessian brown of Ridgway) where bruised, becoming 

 citron yellow to olive brown with blackish areas when dry; fibrils inconspicuous, absent 

 above and appearing as innate ridges below, blackening upon drying, passing into one 

 or more conspicuous and considerably branched rhizomorphs. Peridium when fresh 

 0.4-0.6 mm., not rarely up to 1 mm. thick; outer part citron yellow, glabrous above, 

 thinly felted below, composed of loosely packed, only slightly entangled hyphae, 4.4-1 1/* 

 thick when fresh, septate, without clamp connections, encrusted with pale olive-colored 

 granules; inner part rosy salmon in section when fresh, composed of more closely packed 

 and much entangled hyphae with reddish granules intermingled; when dry more or less 

 reddish brown throughout and not changing color in 7% KOH; 200-300/* thick. Gleba 

 pallid white at first, drying warm buff, not changing when cut, rather tender when fresh, 

 becoming quite brittle upon maturing; tasteless, odor faintly farinaceous; cavities 

 averaging 2-A to the millimeter, labyrinthiform, not rarely up to 2 mm. long in section, 

 empty; septa 90-110/*, averaging about 100/* thick, occasionally scissile, hyphae loosely 

 packed, much entangled and branched. When dry the peridium is only about 200-300/* 

 thick, the outer part 30-80/*, the inner 110-230/* thick. 



Spores (of No. 7207) elliptic, smooth, with two conspicuous droplets, 3-3.7 x 

 6.4-8.5/*. Basidia 6-9 x 18-30/*, with thin, nongelatinized walls; extending out con- 

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

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

 which along with the tramal threads become very much gelatinized as the plant 

 deliquesces. 



We have compared our plants with a specimen of R. roseolus studied by Zeller 

 and Dodge (Whetzel, No. 598; N. Y. State Coll. of Agric. at Cornell Univ.) , kindly sent 

 us by Dr. Fitzpatrick and find that they agree in all respects except for the size of the 

 spores which in the plant from Ithaca are somewhat larger (measuring 3.6-3.9 x 

 8.1-11.1/*) than those of the Chapel Hill plants. 



This plant is closest to R. rubescens and epigeal forms of the latter might easily be 

 confused with the present plant since the exposed surface of R. rubescens is quite often 

 more or less citron yellow. The citron yellow color when present, however, in the 



