28 A. W. Eoans — North American Species of Frullania. 



involucres furnish one or two additional ones : in F. Tamarisci bracts 

 and bracteoles are relatively broader and the distinct stylus of J^. 

 Asagrayana is replaced by a cluster of fine cilia. The leaves of 

 F. Tamarisci, also, are usually somewhat pointed, while the median 

 row of discolored cells is rarely distinct. 



As we go westward F. JVisquallensis, another close ally of JF. 

 Tamarisci, makes its appearance. The leaves of this species are 

 still more sharply pointed, and the reflexed underleaves show basal 

 auricles which are not strongly crispate as in F. Tamarisci. The 

 involucres, also, provide us with important differences ; in F. JSPis- 

 quallensis, the bracteoles, at least the innermost, are connate on both 

 sides with the adjacent bracts, and the lobes of the latter are narrow, 

 acuminate and subentire. 



In addition to F. Nisquallensis, we have in the west the plants 

 which have been known as F. Asagrayana, var. Galifornica. The 

 confusion in regard to these plants has been partially cleared up by 

 Mr. Howe, but it seems best to go still farther than he has done and 

 to recognize two distinct species, instead of trying to retain one of 

 them as a variety of F. Asagrayana. The first of these species, F. 

 Franciscana, resembles the eastern plant in its plane underleaves and 

 in the median line of discolored cells in its lobes ; but the latter is a 

 less striking feature than in F. Asagrayana. and the underleaves are 

 different in shape and never auriculate at the base. The stylus, too, 

 is usually reduced to a minute subulate process and, in the perichsetial 

 bracts, is replaced by a cluster of cilia, a similar cluster being found 

 also at the antical base of the lobe. 



The second of these two species, F. Galifornica, is usually more 

 slender than any of our other Thiopsiellae, and its less imbricated 

 leaves give it a somewhat looser appearance. In the involuci'e, the 

 bracts rapidly increase in size ; so that, while the outer ones are 

 often smaller than the corresponding ones in t. Asagrayana, the 

 innermost bracts are larger : the bases of bracts and of bi'acteoles 

 are much as in the eastern species, but the lobes of the bracts are 

 proportionately narrower. The underleaves are variable ; in rare 

 cases they are slightly auriculate at the base, while their mar- 

 gins are either plane or slightly reflexed on one or both sides near 

 the base, never at the apex. The stylus of the leaves is minute, 

 very much as in Ji . Franciscana, from which the present species 

 differs in the usual absence of the median line of discolored cells, in 

 the shape of its underleaves, and in the characters of its perichajtial 

 bracts and bracteoles. 



