Monotropaceae with Reference to Ericaceae 57 



Kramar says that the fungus is only a parasite drawing its 

 nourishment from the plant. After the outer covering is formed, 

 however, the fungus can then take the place of root hairs and 

 absorb water for the plant. It may also give a part of its own 

 assimilated food to the plant. Frank observes that as the 

 fungus dies each year the plant could then absorb its protein 

 content. Kramar also describes the contents of the subepi- 

 dermal cells, that they are coarsely granular and that these 

 cells represent a storage place where the nutritive material, 

 taken in by the mycelium, lies until ready to be transferred to 

 where it is to be used. He probably saw the starch grains 

 similar in appearance to those of Chimaphila when they had 

 become disintegrated to the extent of not showing a hilum. 



Pyrola elliptica has practically the same appearance as P. 

 rotundifolia. P. secunda is reported to have fungal hyphae 

 by Irmisch (32), Rommel (65), Andres (2), Petersen (60); 

 P. minor by Kramar (44) and Petersen (60). 



P. aphylla is described by Holm (30) as having the root free 

 from hyphae. This seems rather improbable in view of the 

 fact that all the other members of the genus have been reported 

 to have hyphae in the roots. The writer has not been able to 

 get fresh material of this for examination. 



Moneses uniflora is reported by Irmisch (32) to have fungal 

 hyphae in the roots. 



In Monotropa hypopitys (Fig. 1 , 3) Kamienski (39) and Drude 

 (11) describe the root tip as having one to two layers of root 

 cap, Drude claiming that in one variety — hirsuta — there are 

 two layers, and in glabra only one. Kamienski, however, says 

 that the number of layers may vary in the same individual. 

 The material examined shows one to two layers of root cap, the 

 outer layer crushed and flattened. All the cells at the tip are 

 very much alike, differentiation into plerome and periblem 

 occurring some distance back from the tip. Kamienski (39) 

 and Peklo (59) have given complete descriptions and accurate 

 figures of the root tip of M. hypopitys. In the Chimaphila and 

 Pyrola species described the fungus does not seem to invade the 

 root cap region either in the root cap itself, over its surface, 

 or in the epidermal cells beneath. In M. hypopitys, though the 

 epidermal cells under the root cap and the root cap cells are 

 not infested, the mycelium extends over the surface of the root 



