34 THE GASTEROMYCETES OF THE UNITED STATES AND CANADA 



stercoreus (Tulasne) ; fibrils numerous but not prominent, fine, elastic, about the same 

 color as the peridium or darker, composed of septate hyphae, innate-appressed above 

 and not very prominent below; peridium thick, 240-400^, simplex, context meshy and 

 quite loose, stupose, ochraceous-buff to ochraceous- tawny under the microscope; gleba 

 white at first, then yellowish when dry; cavities narrowly labyrinthiform, empty or 

 filled with spores where the cavities are small; septa 60-90p. thick, made up of hyaline, 

 branched hyphae mostly extending parallel with the surface of the hymenium, becoming 

 scissile early; basidia almost entirely collapsed, a few were seen which were completely 

 collapsed only in the distal half, the uncollapsed part about 5.5/u thick; the length of the basidia 

 24-28fi. Spores acrogenous, distinctly colored, ochraceous tawny, usually ellipsoidal, 

 but often irregularly bent or angular, 3.7-4.6 x 8-lly. rarely up to 132y. s smooth, with a 

 vague cup which is often extended into a collapsed filament (a part of the basidium) but 

 spores scarcely truncate. 



In sandy coniferous woods. Cosmopolitan. 



Illustrations: Hesse. Die Hypogaeen Deutsch., pi. 2, figs. 1-4; pi. 5, figs. 5-7; pi. 7, fig. 26; pi. 9, fig. 26. 

 Tulasne. Fungi Hypogaei, pi. 1, fig. 5; pi. 11, fig. 5. 

 Zeller and Dodge. Ann. Mo. Bot. Gard. 5: pi. 1, fig. 4. 



New York. Ithaca. Reddick, coll. (Dept. PI. Path. Herb., 7359, in N. Y. State Coll. Agric. at Cornell 



Univ. and U. N. C. Herb.). 

 Reported by Zeller and Dodge also from Massachusetts and North Carolina. 



Rhizopogon piceus B. & C. 



Plate 107 



Plants irregularly globose, up to 1.5 cm. thick, glabrous, greenish yellow when 

 first dug, soon sordid yellowish and then brown to blackish on exposure and handling; 

 fibrils abundant and netting the surfaces all over, inherent and only sparingly free 

 below, dark brown, several entering the ground and there branching and holding a ball 

 of earth. Peridium 300-500/u thick, single, mottled with dark and light areas, in 

 microscopic section composed of densely packed, small threads about 3.7/j thick, and 

 of dark colored, subspherical to oblong or irregular bodies up to about 10/i long which 

 turn reddish brown in large part when fresh upon the application of 7% KOH. When 

 dry a section in KOH becomes largely black, mottled with pale areas. Gleba brownish 

 yellow, toughish and elastic, the chambers small, 70-300/i broad or long (most about 

 100-200/u), irregular, but less so than in other species, remarkable in being blocked out 

 into small groups by obvious plates; empty at first, becoming densely filled with spores 

 at maturity, lined with a hymenium; septa not scissile or very slightly so, 74— 111/z 

 thick, the context composed of densely packed, much-entangled hyphae about 2-3. 7/i 

 thick. Odor distinct but not nearly as strong as in R. rubescens (No. 6049, etc.), 

 pleasant and suggesting walnuts or wine. 



Spores brown in mass, pale olivaceous when single, smooth, subelhptic with two 

 oil drops, very peculiar in that a good many are slightly to considerably bent and less 

 often deviating to irregular and even subtriangular, occasionally slightly constricted, 

 2.9-3.7 x 7.2-8/x, not rarely up to 11/*. Basidia totally collapsed in dried specimens; 

 in the hymenium are numerous highly gelatinized thick-walled cells. 



According to Dr. Dodge our plants are just like the co-type in the Curtis Herbarium 

 (Hong Kong), including the abundant and conspicuous bodies in the peridium. A 

 note with the Curtis plants says, "Germinating beneath the surface, and by its expan- 

 sion causing small areas of a hand-breadth size to cleave off. Black or brown after 

 exposure." 



