Evans : Hepaticae of Puerto Rico % 157 



In the majority of the species two types of branching are to be 

 observed, very much as in the genus Bryoptcris and in certain 

 other genera of the Lejeuneae Holostipae* In at least one species, 

 however, all of the branches seem to conform to the Lejcunea type, 

 being borne behind leaves with lobules. The Frullania type of 

 branching, in which the subtending leaves fail to develop lobules, 

 is largely restricted to robust vegetative axes. In a branch of this 

 character the subtending leaf is partly inserted on the main axis 

 and partly on the branch, the postical base being slightly revolute 

 (figures 2, 13). The first underleaf is usually distinctly bilobed 

 and is displaced in such a way that the branch seems to arise from its 

 axil. It embraces the base of the branch and partially enwraps 

 the postical base of the subtending leaf. The first leaf is of small 

 size and complicate-bilobed, but the lobule is explanate and rounded 

 at the apex. The succeeding leaves and underleaves are normal 

 in appearance. The Lejennea type of branching, even where it 

 does not occur in the vegetative portion of a plant, is almost 

 invariably associated with subfloral innovations. An exception to 

 this condition, however, is found in the remarkable B. sandvi- 

 censis (Gottsche) Evans, of eastern Asia and the Hawaiian Islands, f 

 In this species the bract behind which a subfloral innovation arises 

 is wholly destitute of a lobule and is partially inserted on the inno- 

 vation itself. 



The inflorescence in Brachiolcjcunca seems to be fairly constant 



for a given species and may be dioicous, autoicous, or paroicous. 

 The female branch varies greatly in length but is usually distinctly 

 elongated. Subfloral innovations are invariably present and usu- 

 ally occur in pairs (figures 4. 5) \ in rarer casei5 onX ? one innova- 

 tion is developed. The innovations are often floriferous and give rise 

 to the false dichotomy which is characteristic of the genus. The 

 bracts are scarcely complicate and the lobe is usually more pointed 

 than in the leaves. In many species a wing is developed at the 

 base of the keel (figures 4, 5)- The bracteole is free or nearly so 

 and varies at the apex from rounded to retuse or shortly bilobed. 

 The perianth scarcely projects beyond the bracts unless the basal 

 portion elongates with the development of the sporoph yte. It is 



, — ^ 



* See Evans, Bull. Torrey Club 34 : 559- *9° 8 - 

 f Trans. Conn. Acad. 10: 4*9» 1900. 



