288 University of California Publications in Botany [Vol. 6 



VII. SPECIAL MORPHOLOGY AND TAXONOMY 



In the following pages the structure of each specimen examined is 

 considered in detail. In certain cases descriptions are necessarily 

 somewhat incomplete, through lack of sufficient data and material 

 This is particularly true in several specimens of which little remains 

 in the Harkness collection, for such characters in these cases as color, 

 size, and shape cannot be determined with accuracy. 



It will be found in the taxonomic arrangement which follows that 

 a number of new names have been proposed, very few of our species 

 being referred to European forms. Even the latter have been so re- 

 ferred with some doubt, for the specimens of the one and descriptions 

 of the other do not entirely agree, and the inability to make compari- 

 sons with European material renders the matter still more uncertain. 

 In general, particular species of the Tuberales do not seem to be rep- 

 resented in both the eastern and western hemispheres, though ap- 

 parently closely related species are found. 



Throughout the following descriptions, spore measurements in 

 every case have included sculpturing. This has not been customary 

 in certain genera, for example Tuber, but it was found impossible to 

 measure the main body of most spores having a thick, deeply colored 

 epispore. In order to avoid confusion, therefore, all measurements 

 were made in the same way. However, in all possible cases in which 

 such addition seems necessary, the thickness of the sculpturing is also 

 cited. 



Hydnocystis Tul. 



Ascocarp even or somewhat lobed, hollow, subglobose, with or 

 without external opening from hymenium, opening when present often 

 more or less closed by dense hairs; surface verrucose, covered with 

 short or long hairs; tissue of ascocarp wall partly or entirely pseudo- 

 parenchymatous ; cavity of ascocarp lined with hymenium consisting 

 of asci and paraphyses in palisade ; asei cylindrical to long club- 

 shaped, rounded at end; paraphyses slender, length of asci or pro- 

 jecting beyond them into interior of ascocarp ; spores globose to globose- 

 ellipsoid, smooth, colorless or of very light color. 



The structure of the ascocarp in this genus is very similar to that 

 in many of tlie Pezizales; and in the Hydnocystis species which open, 

 the plant much resembles an inverted Peziza. Apparently there is no 



