T. Holm — Studies ujpon the Cyperacece 217 



elongated, are, as we know from the literature, very cQ,jiimon, 

 although only a few have been, so far, recorded from this 

 country. Penzig, in his Pfianzen teratologic (1. c), enumerates 

 Carex Fraseri Andr., C. intiimescens Eadge, C. lujpulina — 

 retrorsa and C. utriculata Boott, as showing this peculiar 

 abnormity, but it is indeed much more common in our Ameri- 

 can species, especially among the heterostachyce. 



It is upon the elongation of the rhacheola into a long hook, 

 without llowers, that the genus Uneinia has been established^ 

 while such elongation, but into a straight processus, is per- 

 fectly normal to certain true Carices, e.g. C. microglochin 

 Wahlbg. 



The remarkable Carex cladostachya Wahlbg., of which we 

 have illustrated a lateral inflorescence (Plate II, fig. 8) shows a 

 very singular ramification, which at first glance may seem to 

 be abnormal, but which, nevertheless, is normal for this spe- 

 cies and its allies. Our figure shows a long-peduncled inflor- 

 escence, with an ochrea at the base (oc.) ; there is one terminal, 

 and three lateral inflorescences, which bear female flowers at 

 their bases and male at their apices. These three lateral inflor- 

 escences have developed from the axils of scale-like bracts, 

 and their prophyilon, the ochrea, is in this case developed like 

 a typical utriculus with no flower, however (Plate II, fig. 9) ; 

 it is the rhacheola of this utriculus, or rather ochrea, upon 

 which the female inflorescences and the male flowers are 

 borne. 



Hence we have in C. cladostachya a species which exhibits 

 a true ochrea, an utriculus and a form intermediate between 

 these. 



There are, however, other cases where the utriculus is the 

 only prophyilon of the entire lateral axis. This we have illus- 

 trated in Carex midticaulis Bailey (Plate II, fig. 10), where 

 the lateral female inflorescences are reduced each to a single 

 flower with its utriculus, and supported by a bract, which here 

 has developed into a green leaf with long blade. The female 

 flower shows here a position corresponding to that, which 

 Roeper had observed inside the ochrea, but this prophyilon 

 has here attained the structure of an utriculus, and the rhache- 

 ola has become arrested in its further development. 



This species, C. multicaulis^ belongs to the Phyllostachym^ 

 which are characterized by their leafy bracts, while in the 

 dioecious AcroarrhencE^ the Physocejphalce and LeptocephalcSy 

 the bracts of the female inflorescences are merely developed 

 as scales. The morphological difference between these groups 

 becomes then confined to the very unimportant fact as to 

 whether the bracts are leaf- or scale-like. The dioecious 

 species of the Acroarrhenoe are all known to vary as monoe- 



