Mr. Stephens on Epilobium. 117 



XIV. — Note on Epilobium angustifolium and macrocarpum. 

 By H. O. Stephens, Esq., with remarks by Sir W. J. 

 Hooker*. 



To the Editors of the Annals of Natural History. 



Since the publication of Mr. Leighton^s papers on these 

 plants [Epilobium angustifolium and macrocarpum~\ in this 

 workf, I have received the following remarks from Sir W. J. 

 Hooker, which will probably go far to prove their specific 

 identity : 



^^ With regard to Epilobium macrocarpum, it seems to be 

 what I alluded to in the 1st edition of my ' Brit. Flor.,^ when 

 I remember there was cultivated in our Botanic Garden at 

 Glasgow an American form of this plant {E, angustifolium) 

 with smaller flowers. 



" From America I afterwards received states which seemed 

 gradually to pass into our true angustifolium. To me, I must 

 confess, the characters you and Mr. Leighton have pointed out 

 do not seem sufficient to constitute a species. Are there not 

 intermediate forms ? and can you really distinguish these two 

 when not in fruit ? How do you know your macrocarpum is 

 not Linnaeus's angustifolium ? What does Mr. Leighton mean 

 by saying that E. angustifolium does not bear perfect cap- 

 sules ? If so, how is it so extensively propagated ? and if true, 

 may not that account for the difference in the fruit ? and surely 

 a barren plant ought not to be the type of the species. 



" I have numerous specimens in my herbarium of what I 

 consider E. angustifolium from Mount Olympus to Iceland 

 and Norway in the old world, and from the Atlantic to the 

 Pacific in the new world, and all that have fully formed fruit 

 have it resembhng your macrocarpum. My large and small 

 flowers seem equally to have fruit of the same character.'^ 



It must be acknowledged, that if these plants are distinct, 

 the specific character rests on the size and shape of the cap- 

 sules ; and if these are alike in both, I cannot but agree with 

 Sir W. J. Hooker, there scarcely remains sufficient difference 

 to constitute two species ; for the elaborate descriptions of 

 Mr. Leighton contain nothing tangible, all the remaining dif- 

 ferences between the two forms being of a comparative kind. 

 Having no means of consulting the Linnaean herbarium, I 

 could not be certain my macrocarpum was not the angustifo- 

 lium of that author; for the plant of Linnaeus I rested on the 

 authority of Smith. I now find Linnaeus^s angustifolium is my 

 macrocarpum, although Smith describes and figures in ' Eng. 



* Read before the Botanical Society of London, Feb. 18, 1842. 

 t See vol. viii. pp. 170, 246, 401. 



