— i8 — 



sterile, but the structure of the thallus, which is figured by Miss Haynes, is sO' 

 distinctive that there can be httle doubt about the correctness of the determina- 

 tion. The genus Bucegia is monotypic. The type material was collected by 

 its author, Simeon St. Radian, in the Bucegi Mountains of Rumania, in 1899. 

 Specimens from the same mountains, collected by K. Loitlesberger in 1897, are 

 likewise noted in the original account. The genus is accepted without question 

 by K. M filler,^ who adds a number of interesting details and figures the structural 

 features of the thallus. He was unable, however, to cite any additional localities. 

 In the following year Schiffner^ recorded B. romanica from five stations in the 

 Tatra Mountains of Austria, as well as from the two Rumanian localities. He 

 likewise gave an exhaustive account of the plant and brought out in his figures 

 the morphological characteristics of the male and female receptacles. A few 

 years later he^ reported additional stations in the Tatra Mountains and stated 

 that he knew the plant from ten stations in all in that portion of Austria. Ap- 

 parently no other European localities are known, and the report of the species 

 from British Columbia and Alberta is therefore of unusual interest. 



The genus Bucegia is a representative of the higher Marchantiaceae, the 

 so-called Compositae of Leitgeb. It agrees with Marchantia and Preissia in 

 having compound or dolioform epidermal pores in the vegetative thallus. The 

 inner opening of the pcre approximates the cruciate condition found in Preissia 

 and certain species of Marchantia (for example, M. paleacea Bertol.)^ In other 

 words the cells bounding the opening approach one another very closely and 

 leave a narrow four-rayed space, which may be partially or wholly closed by an 

 increase in the turgidity of the cells. Although the pores are essentially the 

 same as in Marchantia and Preissia the air-chambers and photc synthetic tissue 

 are very different. Instead of being in a single layer the air-chambers are often 

 in two or more layers; while the photosynthetic tissue, instead of being in the 

 form of upright rows of cells, is represented by the walls a single cell thick sepa- 

 rating the air-chambers frcm one another. The type of air-chambers found in 

 Bucegia does not recur in any of the other Compositae but is found in Reboulia,. 

 Asterella and other genera belonging to the group Operculatae of Leitgeb. Here, 

 however, it is always associated with simple epidermal pores. 



The compact tissue below the air-chambers shows none of the sclerotic 

 cells which form so distinct a feature in Preissia and in many of the species of 

 Marchantia. It even lacks oil-bodies and is composed of thin-walled parenchyma 

 throughout. The ventral scales are in two rows, differing in this respect from 

 Marchantia but agreeing with Preissia and the other Compositae. The scales 

 have the usual semicircular or broadly lunulate form and each one bears a single 

 lanceolate appendage. Both rhizc id-initials and cells containing oil-bodies are 

 absent. 



1 Rabenhorst's Kryptogamen- Flora 6: 255-298. /. 180, 181. 1907. 



2 Beih. Bot. Centralbl. 33^: 273-290. /. 1-2^. 1908. 



3 Magyar Bot. Lapok 10: 280. 191 1. 



1 For a description of the morphological features of Marchantia, see Evans, Trans. Conn^ 

 Acad. 21: 208-228. 1917. 



