EXTRACTS FROM FOREIGN PERIODICALS. 487 



■while those of the second ring are only represented by a tuft of down, and those 

 of the first ring have entirely disappeared. — Annates des Sciences Naturelles. 



BOTANY. 



2. Phanerogamous Plants naturalised near Montpellier. By M. 

 Alphonse De Candolle. — Nothing, says M. De Candolle, is more difficult 

 than to prove the introduction of a phanerogamous plant into the European 

 floras. Our countries have long been in communication with the whole world, 

 so that the species which might easily have been introduced have been introduced 

 many centuries before accurate botanists could prove it. If new relations intro- 

 duce, accidentally or voluntarily, new species, the frequent changes of our ex- 

 extratropical climates, aud the extent of our culture (of plants), commonly pre- 

 vents their being naturalised in a lasting manner. How many seeds escape 

 from our gardens, which, nevertheless, cause no addition to the flora of our fields ! 

 How many species have been sown without the boundaries of our cultivated 

 grounds, from which nothing has resulted, or the produce of which has disap- 

 peared after having struggled one or two years with the climate, and with indi- 

 genous plants, exclusive masters of the land. 



Gouan of Montpellier, Grosse of Geneva, and several Parisian botanists, have, 

 during many years, thrown handfuls of foreign seeds into our woods, meadows, 

 and mountains, and, to my knowledge, no one of these is naturalised. 



The following, however, is an instance of successful naturalisation in the neigh- 

 bourhood of Montpellier. Jussicea grandijlora, an aquatic plant of the order 

 Onagracece, a native of Georgia and Carolina, was thrown into the little river 

 Lez, six or seven years ago, by M. Delile, director of the garden of Mont- 

 pellier. It has propagated and naturalised itself in an extent of many leagues, 

 almost so as to obstruct the mill-streams. This year (1836), in September, I 

 have seen it erecting its beautiful yellow flowers in the midst of the Polygonum, 

 Mentha, &c, which have always covered the peaceful waters of the banks of the 

 Lez. It occurs abundantly above the Pont Juvenal ; and if we then repair to 

 the neighbouring inclosures destined for the cleaning of wool*, we can compare a 

 complete and permanent naturalisation with the ephemeral introductions which 

 botanists have frequently mentioned. The fact relative to the Jussicea admits of 

 no doubt. The cause of its success appears to me to be the nature of the station 

 of J. grandiflora. The plants which live more or less submerged in water are 

 commonly found in countries distant from each other. They are, so to speak, more 

 sporadic than the generality of species belonging to the same genera or families. 

 They accommodate themselves more easily to all climates, because the medium 



* The wools of the East, dried at the Pont Juvenal introduce annually some species, but 

 they are not found to spread and multiply in the country. 



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