ON A GRA RIA CEM. 487 



lere are some formed almost exclusively of American species, the 

 most considerable being (Emiliera. To America exclusively belong 

 eleven genera, six of which are monotypes. All the Lopezlece in- 

 habit the south-west of North America and do not descend beyond 

 Guatemala. Hauya and Gongylocarpus have been observed only in 

 the warm parts of Mexico ; Heterogaura and Eucliaridmm like 

 Zausclineria are exclusively Californian. Loiidonia and the section 

 Meionectes of the genus Haloragis are all Australian. The aquatic 

 types, such as Hippuris and Myriophyllon, ascend, on the contrary, 

 to the cold regions of Europe, Asia, and North America. As far 

 south as New Zealand the family is represented by Haloragis^ Gunnera^ 

 and by the latter to antarctic America. Trapa natans exists in 

 Denmark and in Siberia. Myriophijllon extends from the Azores 

 and Algeria to the Orkney Isles and Sweden, and Hippuris, found 

 in the Shetland Isles and Hebrides, exists also at the southern ex- 

 tremity of America. Ludwigia belongs to the warmest parts of 

 America, Asia, and Africa, and by Dantia palustris (Isnardia), they 

 extend from the Cape of Good Hope to the Faroe Isles and in 

 America to Canada. 



The organs of vegetation in these plants present an infinite diver- 

 sity of character, often according to the very different localities they 

 inhabit ; they are however nearly always herbaceous plants, annuals 

 or evergreens, sometimes shrubs, but never in reality trees. Their 

 organs of floration and fructification exhibit great variations, on the 

 most important of which is based the following division into seven 

 series : 



I. (Enothere^.^ — Flowers regular or nearly so. Ovarian cells 

 multiovulate. Style entire or more or less divided at the summit. 

 Fruit dry or fleshy. Seeds without albumen. — 9 genera. 



II. Gaurej].^ — Flowers regular. Ovarian cells (complete or in- 

 complete) uni- or biovulate. Ovules descending, with micropyle 

 inferior and superior. Style not deeply divided or entire at stigma- 

 tiferous extremity, often indusiate at base. Seeds descending, 

 solitary or few, with or without albumen. — 2 genera. 



^ Onagrece DC. Mem. Onagrar. 2. — JussiecB 2 QaurecB Endl. Gen. 1195, tribe 1.—(Eno- 



DC. loc. cit.—Fuchsiea'DC. loc. cii.—? Montiniea therem (part) Spach, Suit, d BuffoHy iv. 338. 

 DC. loc. cit. 1. 



