A BIOLOGICAL JOURNAL 



Vol. IV. OCTOBER, 1893. No. 3. 



SOUTHERN EXTENSION OF CALIFORNIA FLORA. 



BY T. S. BRANDEGEE. 



The flora of the Peninsula of Baja California has usually been 

 considered to be nearly the same as that of Southern Alta California, 

 and Mr. Hemsley for that reason has given it no place in his 

 Botany of the Biologia Centrali-Americana. A region extending 

 through nine degrees of latitude, having California for its 

 northern boundary and its southern portion lying within the 

 tropics, with its northern vegetable life controlled by the alterna- 

 tion of winter and summer and its southern dependent on tropical 

 rains, cannot possess a similar flora throughout its entire length. 



There is a point situated between these extremes of latitude 

 and differences of climate where there is a change in the flora, a 

 change from that of the south to one that is in great part 

 Californian. The middle latitudes of the Peninsula do not seem 

 to have any well defined seasons of vegetable life, and the time 

 of flowering may follow winter rains of the northern climate if 

 they should extend southward, or the summer showers from the 

 tropics when they reach northward. Even as far south as Mag- 

 dalena Bay this shifting of growing season is apparent, and mj 

 own visits there have shown me that in two successive years 

 all the annuals and most of the perennials burst into life with the 

 new year in consequence of the December rains, but during a 

 following year, in January, hardly a flower could be seen, most 

 of the bushes were leafless and the only signs of vegetable life to 

 be found were remnants from the profusion that existed in 

 October after a series of heavy tropical rains. The point at 

 which the most decided change in the flora is seen occurs at 

 about latitude twenty-eight degrees, in the vicinity of El Campo 

 Aleman, and Calmalli, on the divide between the drainage sloping 



