214 T. Holm — Studies upon the Cyperacece. 



Aet. XX Yll. — Studies upon the CyperacecB ; by Theo. 



Holm. 



11. The clado- and antho-prophyllon in the genus Garex. 

 (With Plate II.) 



While the dicotyledonous plants have usually two prophylla 

 developed on their lateral vegetative and floral axes, the mono- 

 eotyledonous have generally only one. An exception from this 

 rule is, however, the presence of only one in some of the 

 Dicotyledones^ e. g. Ranunculus Lingua, R. auricomus and 

 others, while two separate prophylla may occur in some of the 

 Monocotyledones^ viz. : on the vegetative branches of Vallis- 

 neria, Elodea, etc., or at the inflorescence of Narcissus, Gal- 

 anthus and other Amaryllidece. 



Besides being the first leaf or leaves upon the lateral 

 branches, the position of the prophyllon is quite characteristic. 

 In the dicotyledonous plants, the two prophylla are situated to 

 the right and the left of the branch, while in the monocoty- 

 ledonous, the single prophyllon is situated on the posterior side 

 of the branch, thns turning its back towards the mother-axis. 

 As regards the structure of these leaves, they are often more 

 or less scale-like; in the Monocotyledones the prophyllon is 

 generally bicarinate with a few, often only two, nerves, which 

 sometimes run out into two tips, hence the leaf appears as if 

 it had developed from two primordia. In most cases, however, 

 this is not so, at least not in the Graminece, Gyperaceoe, Jun- 

 cacecB and the majority of the Monocotyledones, while in the 

 Amaryllidece the so-called spatha is surely formed by coales- 

 cence of two separate leaves. This is the more apparent since 

 two flowering branches often develop from these spathse. 



By studying the prophyllon in the genus Garex, it is inter- 

 esting to note the various forms in which it becomes modified 

 in normally developed specimens, while it often undergoes cer- 

 tain transformations, in cases, that are truly abnormal. As the 

 title of this article indicates, we might suggest making a dis- 

 tinction between the prophyllon of the vegetative and of the 

 floral axis, and we might, as a mere matter of convenience, 

 name them according to their place " clado- and antho-prophyl- 

 lon." 



The first of these, the clado-prophyllon, belongs, then, exclu- 

 sively to the lateral vegetative axes. It is, in the Garicem^ 

 hardly different from the other scale-like leaves of the rhi- 

 zome, indeed it is generally to be distinguished by its position 

 only, as described above. Since none of the species of Garex 

 develop aerial vegetative shoots under normal circumstances, 



