38 



NATURALIZATION OF PLANTS. 



Is the Naturalization of Plants impossible ? 

 BY M. NEUMAW, I'ARIS. 



[Tun following is a translation of an article 

 in the Annales d'Horticulturc, Paris, which 

 Avas lately read before the Socicte Royalc 

 d'j-/g7iculfure o[ France. M. Neunnann is 

 one of the most intelligent French horticul- 

 turists ; and his opinions are entitled to 

 grave consideration. We think, however, 

 there are some facts well known in this 

 country, and to which we shall hereafter 

 refer, that will tend to prove that the kind 

 of naturalization brought about by sowing 

 the seeds of successive generations, imprac- 

 ticable to a certain extent. But undoubt- 

 edly hybridization is the shortest and most 

 certain road to this result. — Ed.] 



It has often been said, in the meetings of the 

 Royal Agricultural Society, that the naturalization 

 of plants is an eas}' ami a natural process. Its ad- 

 vocates have even frequenti}- cited as illustrations, 

 plants originally from warm latitudes which they 

 say arc now naturalized here. I have heretofore 

 dissented from this opinion, and I wish, at the 

 present moment, by the aid of additional fact and 

 experience, to tiemonstrate the impossibilitj- of the 

 naturalization of plants. In short, I wish to unde- 

 ceive those, who, resting on this baseless theory, 

 as hitherto held, still indulge the hojie of enrich- 

 ing our soil with exotics that nature has only be- 

 stowed on favored climates, whose mean tempera- 

 ture is much higher than our own. 



I am not however alone in this belief with rcgai-d 

 to naturalization. In 1S30, M. Poiteau. my friend 

 and colleague, explaineil its impossibility to the 

 class of pupils at the Horticultural Institute of Fro- 

 mont. Later, in 1837 and 1S42, he read before 

 the Royal Horticultural Society two striking essays, 

 showing the fallacy of this theory. I have now, 

 therefore, the greater satisfaction in this coinci- 

 dence of opinion, as I am about to bring the sub- 

 ject before you, and olfer some new arguments 

 against the theory of naturalization. 



I ought to state in the outset, that the words 

 naturalization and acclimation, as applied to plants, 

 are nearly synonymous in my mind. In combat- 

 ting one, I wish to lA understooii as equally oppo- 

 sing the other. 'I'he venerable and honoiable 

 Andre Thouin, whose memory we must always 

 greatly respect, was not perhaps the first who 

 believed that vegetables gradually become natu- 

 ralized. Eut he was the lirst who attempted to 

 establish the doctrine, now more than half a centu- 

 ry ago, trusting as he did, that it would benefit his 



countrymen; for his leading motive in life was (lie 

 promotion of the good of his fellow creatures. Hut 

 unhappily nature's laws ilo not always accord with 

 our theories; and since Thouin laid ilown the rules 

 for the naturalization of plants, that is to enable 

 them or their descemianls to withstand a tenijie- 

 rature much colder than that of the climate where 

 they originated, we have not had the satisfaction 

 of seeing any of these plants become really hardy, 

 so as to bear the rigors of our climate. 



Thouln's rule for naturalizing a plant, so as to 

 render it or its seedling hardy, was briefly as fol- 

 lows: 



" j1 jdant from a tropical country must be grown 

 in the hot-house until it produces seeds. These 

 seeds must be sown, and the plants raised from 

 them cultivated until they in turn produce seed^i. 

 The same process is repeated with the seeds of this 

 generation, and by continuing this, (always sow- 

 ing the first and freshest seeds) from three to ten 

 generations, we obtain, at last, naturalized plants 

 — in other words, hardy plants, capable of bearing 

 our winters.'^ 



I cannot but appeal to the members of this soci- 

 ety for the proofs of this kind of naturalization? 

 Seeds were often sown in the very mode pointed 

 out by Thouin before his time; we are now raising 

 seedlings in the same way eveiy day. And yet 

 we have never obtained a plant more able to re- 

 sist the winters, out of doors, than the original 

 parent specimen. 



Thouin has told us that in this way the large 

 Nightshade, (Belle de A'uit,) is naturalized in 

 France. But really this plant is by no means natu- 

 ralized. In India, its native country, it is a peren- 

 nial, and although it has now been cultivated from 

 seed here almost 300 years, its roo s still freci e 

 and perish every winter in our climate in the open 

 border. 



'I'he author adds tha' in the same v/ay the Cycla- 

 men d'Asie, the Sainfoin manne dcs Isra Ittes, the 

 Luzerne de Ah'die, and many other foreign plan s, 

 have been naturalized in this country; but he does 

 not tell us at what attitude these plants grow where 

 they arc natives. He does not, thei-efore, atfoi-d us 

 any proof that they do not really exist in their na- 

 tive habitats in an atmosphere greatly likeiuir own. 

 In short, of llie four examples of nalui-alizat on, 

 cited by M. 'I'houin, one of them stands without 

 evidence, and the other three are far from being 

 well supported by proofs. 



As to naturalizing |)lunts from latitudes much 

 warmer than Paris, by cultivating them first in the 

 hot-house, afterwards in the green house, and 

 linally in the ojien air, it is a theory with no bet- 

 ter foundation. Such of these plants, so treated, 

 that were not able naturally to stand our winters, 

 have never yet been brouglit to do so; anil those 

 which appear somewhat hardy, were really as much 

 so, had they been testcti the first season they were 

 introduced. Thus, although we have cultivated 



