68 Henderson — Comparative Study of Pyrolaceae and 



In Monotropa hypopitys, the epidermal cells are similar to 

 those preceding. Stomata are present though rather rare. 

 Previous investigators are unanimous in saying that stomata 

 are absent on the flowerstalk (9. 48, 73). The writer finds 

 two types of stoma — the normal type with the slit parallel 

 to the longitudinal axis (Fig. 4, 4) and that with the slit trans- 

 verse to the longitudinal axis (Fig. 4, 5). The first type is 



Fig. 4. Stomata X 290. 



1. On lower epidermis scale of Monotropa uniflora 

 2-IO. On epidermis of ascending axis of: 

 2-3. Sarcodes sanguinea 

 4-5. Monotropa hypopitys 

 6-10. M. uniflora 



more frequent in M. hypopitys. The guard cells are extremely 

 large and often much distorted. Whether or not these stomata 

 function one cannot say, but their presence indicates that they 

 were functional at one time, at least when the plant was young 

 and before the guard cells were pulled apart by the rapid upward 

 growth of the flowerstalk. Unicellular hairs with ridged cuticu- 

 lar thickenings are present on the epidermis. 



