86 BAHIA BLANC A TO BUENOS AYRES. [CHAP. vt. 



is likewise much perplexed by the immediate appearance of plants not 

 occurring in the neighbourhood, on the borders of any track that leads 

 to a newly-constructed hovel. In another part he says,* " ces chevaux 

 (sauvages) ont la manie de preTerer les chemins, et le bord des routes 

 pour deposer leurs excre'mens, dont on trouve des monceaux dans ces 

 endroits." Does this not partly explain the circumstance? We thus 

 have lines of richly-manured land serving as channels of communication 

 across wide districts. 



Near the Guardia we find the southern limit of two European plants, 

 now become extraordinarily common. The fennel in great profusion 

 covers the ditch-banks in the neighbourhood of Buenos Ayres, Monte 

 Video, and other towns. But the cardoon (Cynara cardunculus)f has a 

 far wider range: it occurs in these latitudes on both sides of the 

 Cordillera, across the continent. I saw it in unfrequented spots in 

 Chile, Entre Rios, and Banda Oriental. In the latter country alone, 

 very many (probably several hundred) square miles are covered 

 by one mass of these prickly plants, and are impenetrable by 

 man or beast. Over the undulating plains, where these great beds 

 occur, nothing else can now live. Before their introduction, however, 

 the surface must have supported, as in other parts, a rank herbage. I 

 doubt whether any case is on record of an invasion on so grand a scale 

 of one plant over the aborigines. As I have already said, I nowhere 

 saw the cardoon south of the Salado ; but it is probable that in propor- 

 tion as that country becomes inhabited, the cardoon will extend its 

 limits. The case is different with the giant thistle (with variegated 

 leaves) of the Pampas, for I met with it in the valley of the Sauce. 

 According to the principles so well laid down by Mr. Lyell, few 

 countries have undergone more remarkable changes, since the year 1535, 

 when the first colonist of La Plata landed with seventy-two horses. 

 The countless herds of horses, cattle, and sheep, not only have altered 

 the whole aspect of the vegetation, but they have almost banished 

 the guanaco, deer, and ostrich. Numberless other changes must 

 likewise have taken place ; the wild pig in some parts probably replaces 

 the peccari ; packs of wild dogs may be heard howling on the wooded 

 banks of the less frequented streams ; and the common cat, altered into 

 a large and fierce animal, inhabits rocky hills. As M. d'Orbigny has 



* Azara's " Voyage," vol. i., p. 373. 



j- M. A. d'Orbigny (vol. i., p. 474) says that the cardoon and artichoke 

 'are both found wild. Dr. Hooker (Botanical Magazine, vol. lv., p. 2862), 

 has described a variety of the Cynara from this part of South America under 

 the name of inermis. He states that botanists are now generally agreed that 

 the cardoon and the artichoke are varieties of one plant. I may add, that 

 an intelligent farmer assured me that he had observed in a deserted garden 

 some artichokes changing into the common cardoon. Dr. Hooker believes 

 that Head's vivid description of the thistle of the Pampas applies to the 

 cardoon ; but this is a mistake. Captain Head referred to the plant, which 

 I have mentioned a few lines lower down, under the title of giant thistle. 

 ^Whether it is a true thistle, I do not know ; but it is quite different from the 

 , \rdoon ; and more like a thistle properly so called. 



