312 THAXTER. 



Endogone MACROCARPA Till. 



Tulasne (1851), p. 182, PI. XX, fig. 1. Bucholtz (1912), p. 184, figs. 62-74. 



Nee Harkness (1889), p. 279. 

 Glomus macrocarpus Tul. (1845), p. 63. 

 Endogone australis Berk. (1860), p. 270. 



Bucholtz (1912) gives an extended summary of the occurrence and 

 spore-variation in this species, which indicates that it is perhaps the 

 most frequently observed and variable member of the genus. The 

 only records of its occurrence in America are that of Lloyd (1908), who 

 reports it somewhat doubtfully from the Bahamas; and that of 

 Harkness (1899) who speaks of finding it under Libocedrus at Towles, 

 in the Sierra Nevada Mountains, California. Mr. Lloyd informs me 

 that the Bahama specimen, which was doubtful, and may have been 

 E. fulva, has been lost; so that this record must remain very 

 dubious. The California form, which I have examined, proves, as 

 above stated, to be E. lactifltia and is identical with what I have called 

 by this name from the East. The spores are clearly zygospores, and 

 the hyphal envelope is well developed, although the " flammenkrone " 

 are not so strikingly differentiated as in some of the Hesse specimens, 

 in the Farlow Herbarium. 



In New England I first encountered what I have regarded as this 

 species, growing on earth in greenhouse pots at the Botanic Garden 

 in Cambridge, in company with Hymcnogastcr Klotschii and Ilydnan- 

 gium carneum, a habitat and association which has also been noticed 

 in Europe. Of this material, one gathering made in the winter of 

 1891-92, has spores seldom exceeding 100 n in greatest diameter, while 

 a second gathering made two years later from the same pots, has spore- 

 masses in which the larger spores measure from 170-200 jj. in greatest 

 diameter. In neither of these was any definite peridium developed, 

 possibly owing to the fact that both grew on the surface and were 

 subjected to constant watering. 



In addition to these two gatherings, seven others have been made at 

 Kittery Point, Maine. In these instances the fungus was found in 

 moist coniferous and deciduous woods, usually just below the leaf cover 

 rarely on the surface; the spore-masses usually solitary, or but two 

 or three together. This material also shows a considerable range of 

 variation in the size of the spores; although a majority correspond in 

 this respect to the first gathering above mentioned. The larger spores 

 are in general 80-100 fx in greatest diameter. This average maximum 



