Southern extension of North American flora. 
339 
laceae in the western hemisphere are limited to the lower Sonoran climatic 
zone in North America and its corresponding zone in Chili and Argentine. 
The following is a tabular statement. 
North America. 
Fagonia cretica L. var. califor- 
ica Benth. 
Guaiacum parvifolium Planch. 
Mexico, 
Guaiacum Coulteri A. Gray. 
Mexico. 
Porlieria angustifolia A. Gray. 
exas, Mexico. 
Larrea mexicana Moric. 
Tribulus terrestris L. 
Tribulus californicus S. Wats. 
Tribulus (Kallstroemia) maximus. 
S. Texas, N. Mex. 
Tr. (Kallstroemia) grandiflorus 
B.&H exas to California. 
West Indies, S. Brazil, 
Northern So. America. 
Guaiacum officinale L. Fla., 
Antilles, Guiana, Venezuela. 
Guaiacum sanctum A, 
Bahamas, Antilles, Coikaei. 
Bulnesia arborea Engl. Co- 
mbia, Venezuela. 
Tribulus terrestris L. 
Tribulus (Kallstroemia) maxi- 
mus L 
Viscainoa gemmulata Lower California. 
Chitonia mexicana Moc. & 
ee Greggü A. Gray. N. Aiherlen: 
anum mexicanum A. Gray. N. Mexico. 
Chili, Argentine. 
Fagonia cretica L. var. cali- 
fornica Hook. 
Porlieria hygrometra Ruiz & Pav. 
N. Chili, Peru. 
Porliera Lorenzii Argentine. 
B. Bonariensis Griseb., Schicken- 
dantzii Hieron., chilensis C. 
ce 
Larrea divaricata Cay., euneifolia 
nitida Cav. 
Tribulus terrestris L. 
Tribulus maxi- 
mus L 
(Kallstroemia) 
The semi-tropic xerophilous forms of Gulf distribution occupy the Rio 
Grande plain in Texas and Mexico below Eagle Pass. 
occur in areas of Colombia, Venezuela, Guiana, Brazil, Uruguay, 
and Argentine and in similar areas of the Antilles. 
According to BRAY the following plants are ses: 
sea-coast species. 
Sida leprosa. Uruguay, Pat 
Sida hastata A. St. Hil. 
Such species also 
Paraguay 
Some are undoubtediy 
tagonia, Argentine, Cuba, north to nern aa 
Argentine, Uruguay, Mexico, Texas 
, Ariz 
Sida air A.St. Hil. Mattogrosso, Uruguay, Argentins, Hohe, Cuba, Florida, Texas, 
Mexie 
Fugosia enfngosi) sulphurea Garcke. 
Spergularia platensis Fenzl. 
Polygala paludosa A. St. Hil. 
It is appropriate to conclude these comparisons with the fl 
Sonthwest Texas, ira, Sonth Brazil, Paraguay. 
Texas to California, South Brazil. 
Brazil, Paraguay, Louisiana and Texas. 
oras of extra- 
American regions with an expositions of the extensions southward through 
the Andes and the antarctic islands to Australia and New Zealand. The examples 
are not numerous, but they are unmistakable. 
22* 
