42 2 Farr on British Columbian Plants. 



As originally defined by Rafinesque and Ptirsh it is 

 scarcely possible accurately to determine which of the above 

 species is intended from the descriptions, since the salient 

 points of distinction are entirely overlooked. In the more 

 recent descriptions of Trelease and Howell, and also from 

 the study of specimens distributed by Howell, the specific 

 name Myrsinites should be restricted as above given. The 

 flowering period of both is about the middle of June. 

 Although not included in the definition there seems a strong 

 reason for believing that the flowers are gyno-monoecious, 

 there being a few blooms with large protruding ovary and 

 rather rudimentary stamens, while the majority of the flow- 

 ers have well-developed stamens and a deeply-sunk recep- 

 tacular ovary. Future study alone can settle these points. 

 From all the material collected by the writer and examined 

 in herbaria, the flowers of each succeeding season seem to 

 develop in the preceding autumn, and remain in bud condi- 

 tion throughout the winter, much as in Dogwood and Japa- 

 nese Paulownia. A study and comparison of these forms 

 over wide areas of Western North America is highly to be 

 desired. 



In order to determine more accurately possible points of 

 difference between these species, a histological study has been 

 made with the following results : 



Pachystima Myrsinites, Raf. — Cork broad, black extern- 

 ally in a broad zone, brown internally in a rather narrower 

 zone. Cortex with few conglomerate crystal cells, scleren- 

 chyma strands in the collenchyma feeble or mostly absent, 

 ^clerenchyma elements of inner cortex scattered in patches of 

 eight to five or even solitary, but in a pretty continuous line. 

 Wood dense. Pith cells all heavily indurated; abundantly 

 starch-storing. Leaves with lower epidermal cells one-third 

 smaller than next, walls straight or slightly wavy and stomata 

 relatively abundant ; the median vascular bundle of the mid- 

 rib with a sclerenchyma strand beneath the phloem that is 

 comparatively small in amount, leaf below the strand flat and 

 with epidermal cells scarcely swollen. 



