COMPOSITAE OF PERAUSTKAL AMEKICA. 181 



THE COMPOSIT.E OF PERAUSTKAL AMEPJCA. 

 By Professor George ISIacloskie. 



(Continuation.) 



The llelianthoideae, or Sunflowers, are essentially an Amer- 

 ican group, and seemingly of ancient origin, having several iso- 

 lated genera ; are chiefly tropical or warm-temperate. Those in 

 Patagonia are chiefly confined to its northern regions, and we 

 miss such ISTorth American genera as HeUanthus, Coreopsis and 

 Budhechia; but the monoecious genera are found, as Ambrosia 

 (the American Ragweed, with the habit of the European Senecio 

 jacobea). This species, and Xanthium , the cosmopolitan Bur- 

 dock, have lost many of the chief marks of Composite, as the 

 synanthery, and the lig-ulate corollas of the female flowers. It is 

 said that Xanthium spinosum L. came originally from Chili, 

 though long before the days of Columbus it was spread over Eu- 

 rope, and it has recently reached Australia. Xanthium, itali- 

 cum Mor., though first described from Italy, is deemed to have 

 still earlier been in Chili, and still exists there and in Xorth 

 Patagonia. Partheniura hysterophorus L. is found from Texas 

 to X. Patagonia; and Wedelia huphthalmiflora Ltz. is found in 

 Eurasia, Africa, Australia and Korth Patagonia. Spilanthes is 

 tropically cosmopolitan, mainly American, and its species 8. 

 arnicoides DC. (a creeper with opposite leaves and long-headed 

 scapes) is the "nim-nim," or chewing-root of the natives. The- 

 lesperma has its involucral scales connate half way up. Madia, 

 the Tarweed, with 1-seriate, carinate, involucral scales, is culti- 

 vated in Chili for the sake of its seeds, which yield oil. 



The ITelenioids, though chiefly a West- American tribe, are 

 not very largely represented in Peraustral America ; but Flave- 

 ria australasica Hook., an Australian species, is thought to be 

 closely allied to, if not identical with, an undescribed form in 

 Southern Argentina. 



The Anthemidese are eminently an Old- World, non-tropical 

 tribe, and are best known by their dry, often scariously tipped 



