ioo ROSE, APPLE, ONAGRACEAL. [CHAP. 



said to be wind-borne. In other respects these two 

 plants are curiously similar. 



There is almost as much difference of opinion with 

 reference to the specific limits in the genus Rosa as 

 is the case in Rubus. Bentham admits five British 

 species, while others, as, for instance, Babington, ex- 

 tend the number to fifteen or twenty. The flowers do 

 not appear to secrete honey, but are much visited by 

 insects for the sake of the pollen. The numerous 

 stamens ripen at the same time as the pistil, but 

 from the convenient position of the latter, insects 

 very frequently alight upon it, and thus fertilise it 

 with pollen from other flowers, though self-fertilisa- 

 tion probably often occurs. 



Pyrus mains (the Apple), on the contrary, and Cra- 

 tcegus oxyacantha (the Hawthorn) are melliferous, and 

 the stigma comes to maturity before the anthers. 



ONAGRACE^:. 



This order contains six English genera, Epilobium 

 QEnothera, Ludwigia, Circaea, Myriophyllum, and 

 Hippuris. 



The instructive differences which exist between the 

 different species of Epilobium have already been 

 referred to in the introductory chapter. (Enothera 

 biennis is really a North American plant, though 

 now naturalized in some parts of England. As its 

 name denotes (Evening Primrose) it is a yellow night 

 flower ; it secretes honey, and is probably fertilised by 

 moths, though it remains open by day, and is also 

 visited by bees. Ludwigia contains a single species, 



