228 Flora of the Cape Region. [ZOE 
their relation to the floras of neighboring regions, especially the 
Mexican main land, is based upon 732 species. These are the re- 
sult of collections made by Dr. Hinds of H.M.S. Sulphur in 1839, 
at Cabo San Lucas; by L. J. Xantus de Vesey in 1859-1860, about 
the same place; by Dr. Edward Palmer at La Paz in 1890, and by 
the writer at various localities during three trips in 1890 and 1892. 
Seventy-two species or nearly ten per cent. of the whole number 
seem to be endemic and future exploration together with the identi- 
fication of unnamed specimens may increase this proportion, al- 
though a more complete knowledge of the botany of Sinaloa and 
Sonora will probably show that some plants now considered peculiar 
to the Cape Region only appear so on account of our ignorance 
concerning their distribution. Three hundred and sixty-two of the 
Cape Region species are found growing on the peninsula from Mag- 
dalena Bay and Comondu northward, and nearly one-half of this 
number extend into Alta California; sixty-four of them are peculiar 
to the peninsula. 
Mr. Hensley in Biologia Centrali-Americana, iv, 139, considers 
Mazatlan the southern limit of the North Mexican flora upon the 
west coast; assuming this to be correct, nearly five hundred of the 
species belong to that flora, and with few exceptions they all belong 
to the flora of Sonora. ice 
The adjacent mainland, Sinaloa, has not been as well explored 
botanically as Sonora, but judging from our scanty data the Mex- 
ican part of the Cape Region flora bears much less resemblance to 
it than to the more northern Sonora, and the flora as a whole is de- 
cidedly that of Sonora and not an extension of that of Alta California 
southward as has usually been supposed. The few plants that 
probably belong to a more southern flora are found along the 
_ Shore or in the southeast about San José and Miraflores. 
Some of these semi-tropical maritime and brackish-water plants 
are found also on the southern end of the Peninsula of Florida. 
Rhizophora, Conocarpus, Avicennia, Laguncularia, omea Pes- 
capre and acetosefolia and Scevola Plumieri are common to Amer- 
ican tropical shores, and reach their northern limit at about the 
same latitude on the Peninsula of Baja California as on that of 
Flotida. -The number common to this region and Florida, how- 
ever, is not large, and of about twenty-five having such wide spread 
distribution, some like Samolus ebracteatus and Centunculus mint- 
