HYDROPTERIDES. 



1. MARSILEA, Linn. 

 1. Marsilea quadrifolia, Linn. 



Marsilea quadrifolia, Linn.; Willd. Spec. PI. 5, p. 538; Kaulf. Enum. Fil. p. 271; 

 Blume, Enum. PI. Jav. 2, p. 273. 



Hab. Feejee Islands; in pools of still water, and plantations of 

 Galadium esculentum. 



This species has a very extensive geographical distribution, being 

 found, we believe, in all the four quarters of the globe. The veins 

 in this, as in the two following species, radiate from, and fork near 

 the base of the leaves ; the veinlets repeatedly anastomosing before 

 reaching the margin, forming long linear meshes ; with a more deli- 

 cate set of reticulated nerves occupying the area within the meshes : 

 these nerves in the present species, are readily detected by the assis- 

 tance of a common lens. 



2. Marsilea villosa, Kaulf. 



Marsilea villosa, Kaulf. Enum. Fil. p. 272. 



31. vestita, Hook. & Grev. 1c. Fil. t. 159; Hook. Fl. Bor. Anier. 2 ; p. 268. 



Hab. Oregon ; in the vicinity of Fort Wallawalla : in lands subject 

 to inundation. California ; in the valley of the Sacramento River. 

 Oahu, Sandwich Islands; near Waianae and between Honolulu and 

 Ewa: in moist places. Hunter River, New South Wales; on the 

 margins of ponds. 



