AUSTRAL-AMERICAN REGIONS. 



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to the Families : but in confining the record to a single line of descrip- 

 tion, the original notes were often abbreviated ; a portion being omit- 

 ted, while in other instances, further details were added. 



The following plants were found growing around the mouth of the 

 Rio Negro in Northern Patagonia : 



" Cheiranthus ? " (No. 1). Vestiges observed by Mr. Brackenridge ; but the specimens 

 lost before they could be critically examined.* 



Lepidium (No. 9). On the tract of sand-hillocks, between the water-line and the Upland 

 plain ; possibly only naturalized. 



Polygala (No. 20). Having much of the aspect of a Polygonella. On the tract of sand- 

 hillocks, rare. 



Silene (No. 14). Annual. On the tract of sand-hillocks, and elsewhere. 

 Spergularia (No. 5; compare No. 3 North California). Stipules; and a large woody root. 

 (Palavia, No. 1; see Lamarck, 577, 2). Prostrate; the flowers large, with a two-leaved 

 outer calyx. 



(Modiola reptans, St. Hil.; No. 1); gen. Malvac. Potentilliform ; the leaves dissected; 



the flowers devoid of an outer calyx ; the petals red. 

 Melochia (No. 1). The flowers very small. 



Oxalis (bipartita, St. Hil. ?; No. 21). The leaflets so deeply divided as to appear each 

 two-horned. Rare. 



(Larrea, No. 1); gen. Zygophyllac. A (large) bush, frequent on the "campos" or Up- 

 land plain. 



Gen. Celastrac. ? (No. 1). Colletia-like ; a spiny shrub; the leaves fasciculate, ovate, en- 

 tire, pointed. 



Gen. Celastrac? (No. 1). A shrub; the leaves perennial, verticillate, ovate-lanceolate, 

 crenate, Euonymus-like. 



Condalia? (No. 1). A spiny shrub; the leaves alternate, obovate, entire ; the calyx of five 

 deciduous sepals ; the stamens five ; the drupe oblong, hard, and coriaceous. 



( ? No. 2). A shrub ; the leaves larger, obovate, entire ; the berry round, contain- 

 ing a single hard seed, that bears some resemblance to the fruit of an Umbelliferous 

 plant. 



Gen. Legum. (No. 1). A large shrub; with deciduous leaves; and a thick fleshy pod. 

 Frequent. 



Gen. Legum. (No. 1). Habit of Galega; the flowers purple; the pod moniliform, three- 

 seeded. Frequent. 



Astragalus (No. 16; perhaps a congener of Phaca villosa of our Southern States?). 

 Annual. Growing on the tract of sand-hillocks. 



* The plants that accompany the footsteps of man, do not in general well endure shade ; 

 but in various countries naturally unwooded, meet with no obstacle to their diff"usion ; one 

 method of detecting them having at the same time disappeared. In the absence of cul- 

 tivation at the mouth of the Rio Negro, I was surprised at the number of foreign plants 

 naturalized : some of which, in considering the course of intercommunication, appeared 

 to have been brought by sea direct from the United States. 



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