438 T. Holm — Studies in the Cyperacew. 



structure does not seem to be influenced to such an extent as 

 to render it impossible to detect several and very gradual tran- 

 sitions. The modern, but often too superficial and hasty 

 classification of plants as Xero- and Hydro-phytes, is not by 

 any means applicable to our genus, at least not to its North 

 American representatives. If such types of plants, Xero- and 

 Hydro-phytes, really exist, it must be proved not by observa- 

 tions in the field alone, but by a very close study of their struc- 

 tural peculiarities. The mere fact that such and such species 

 inhabit dry, sandy places or marshes, ponds, etc., does not 

 necessitate the plants in question to be considered as either 

 xero- or hydro-philous species ; their internal structure must 

 be carefully examined before any conclusion can be drawn, as 

 to whether these plants are " solely adapted" to these special 

 environments. As regards our species of Fimbristylis it 

 might seem very tempting to classify these in this way : F. 

 capillar is, F. Warei, F. stenophylla and F. ciliatifolia as 

 xerophytes, and the remaining species as hydrophytes, but 

 their anatomical structure does not seem to justify any such 

 classification. In order to facilitate the anatomical comparison 

 of the material, which we have examined, it may be well to 

 enumerate the various localities as follows : F. autumnalis was 

 collected in wet sandy or clayish soil in the vicinity of 

 Washington, D. C, and in low sandy places near Eustis, sub- 

 tropical Florida ; F. castanea was from brackish marshes near 

 the coast of Maryland ; F. spadicea and F.puberula both from 

 wet, sandy soil near Eustis, Florida ; F. laxa from low meadow- 

 .land, rather dry soil, near Brookland. D. C, as well as from 

 low, sandy soil near Eustis, Florida ; F. tkermalis from hot 

 sulphur springs near Golkonda, Nevada ; F. capillaris from 

 dry, sandy soil near Washington, D. C, and Eustis, Florida; 

 F. ciliatifolia from dry, sandy fields in Alabama, and finally 

 F. stenophylla and F. Warei from dry, sandy soil in the High- 

 Pine-woods near Eustis, Florida. Besides these we have, also, 

 examined some specimens of F. complanata and F. capillaris 

 from Montevideo, Uruguay, which together with a number of 

 other Gyperacem were presented to the writer through the 

 courtesy of Professor Arechavaleta, Director of the National 

 Museum at Montevideo. 



In discussing the anatomy of the vegetative organs of these 

 species, we will begin with 



The leaf. 



By its greater ability to vary, the leaf appears to illustrate 

 the species better than the stem or root. Considering the 

 mere outline of the leaf, three types are readily distinguished : 



