426 TRANS. OF THE ACAD. OF SCIENCE. 



that in some species, at least, soil and moisture have a most 

 important influence on them, as they also have on the devel- 

 opment of the inflorescence; the overgrown forms of J. 

 scirpoides, as I understand that species, have large, laterally 

 compressed, gladiate leaves, while in the forms grown on 

 drier and poorer soil the leaves become almost or entirely 

 terete. On the other hand, the peculiar tribe of articulate 

 Junci of the Pacific slope, which I have called Ensifolii 

 from their characteristic sword-shaped leaves, exhibits, in 

 alpine situations, such narrow leaves that they might inad- 

 vertently be mistaken for terete ones. 



Inflorescence. — The inflorescence offers us important but, 

 to a surprisingly great extent, variable characters. All Junci 

 have as is well known, a terminal inflorescence, even where 

 it is 'seemingly lateral. In the Californian sub-genus Jun- 

 cellus and in a few South American and antarctic species 

 which form the sub-genus Bostkovia (gen. Bostkovia, Hook, 

 f., Bostkovia, Desv., and Marsippospermum, Desv., in part), 

 a single flower terminates the stem or scape ; but all the true 

 Junci have a more or less compound inflorescence of single 

 flowers or of flowers crowded into larger or smaller heads. 



In the inflorescence we observe numerous bracts, usually 

 of a membranaceous texture; the uppermost bracts bear in 

 their axils the flowers, which are always lateral, though in 

 the species with single flowers they appear terminal. In 

 these the lower of the two highest bracts, which are always 

 found at the base of the flower and which were therefore 

 termed " calyx" by Rostkovius, bears the flower in its axil, 

 the upper one remaining sterile; but the trace of an axillary 

 product, an abortive flower or a leaf-bud, ought occasionally 

 to be found, as is regularly the case in J. pelocarpus. In the 

 single flowered forms of this species the uppermost bract 

 usually bears an abortive bud, or this bud grows out into a 

 leafy branch, or it becomes a second flower; and then a third 

 bract is formed, often again with a leaf-bud, but never, so far 

 as I know, with a third "flower. Thus we have the complete 

 transition from the single flowered to the species in which 

 the flowers are grouped into heads. In these each bract 

 bears in its axil a flower in centripetal succession, the upper- 

 most minute bracts remaining sterile in the center of the 



head. 



The single flowered Junci bear panicles, or, as k. Meyer 

 and many botanists after him called them, anthelce, of differ- 

 ent form and development. In some species (e. g. in the 

 common forms of J. tenuis and J. dichotomus) the panicle 

 has often the shape of an almost regularly dichotomous cyme, 

 or at least the main branches are dichotomously divided ; in 

 most other species this regularity is considerably obscured 

 by the development of many elongated branches from a short 



