310 FLORA OF SOUTH AMERICA AND THE PACIFIC. 



XXlll Contributions towards a Flora of South Aml- 



RicA, and the Islands of the Pacific. By Sir W. J. 

 Hooker, K.H., LL.D., and G. A. Walker Arnott, 

 Esq., LL.D. 



I. Extra-Tropical South America. 



( Continued from page A*l , of the present Volume.^ 

 TriB. VIII. SENECIONIDEiE, LeSS* 



1121. (1.) Xanthium macrocarpum, DC. FL Fr. et Prodr. 

 V. p. 523. — X. orientale, Linn.fil. — Buenos Ayres; Tweedie. 

 Quillota, Chili; Bridges, (w. 514). Mendoza; Dr Gillies. 



1122. (2.) X. spinosum, L. ~ DC. Frodr. v. p. 523 — X. 

 catharticum, H.B.K. Nov. Gen. Am. iv. p. 274. DC. Prodr. 

 p. 523. — Desaguadero, Province of San Luis, and Mendoza; 

 Dr Gillies. Chili; Bridges^ (n. 511.) Cuming., (w. 90.) Buenos 

 Ayres; Ttceedie. — We scarcely think Humboldt's plant can 

 be distinct from ours. Cathartic powers are stated by Hum- 

 boldt to be attributed to it. Tweedie remarks that it has 

 the property of rendering meat that has been almost putrid, 

 sweet. 



1123. (3.) X. ambrosioides {Hook, et Arn.) ; spinosum 

 tomentoso-incanum, caule procumbente, foliis bipinnatifidis, 

 segmentis oblongis obtusis margine revolutis, capituli foemi- 

 nei solitarii aculeis tenuibus setiformibus patentibus apice 

 uncinatis, spina terminali valida recta. — (3. capituli foem- spi- 

 na valida nulla. — Los Caldanes, Province of Cordova; Dr 



Gillies. Buenos Ayres; Tweedie This very distinct species 



has the finely cut foliage o( Ambrosia, and the fruit of Xan- 

 thinm. The terminal spine of the female capitulum is fre- 

 quently wanting. 



1124. (1.) Ambrosia tenuifolia, Spr. — DC. Prodr. v. p. 

 527.— Saladillo to El Morro, province of San Luis ; Dr Gil- 

 lies. Buenos Ayres and Maldonado; Tweedie, (n. 1055.) 



* It will be borne in mind that our general arrangement of the Compo- 

 site, is that of Leasing ; our mst. having been prepared, and much of it 

 printed before the puMication of the oth and 6th volumes of Dc Candolle's 

 Prodro}nus. 



