NOTES ON THE NATURALIZED PLANTS OF 
SOUTHERN CALIFORNIA. I. 
GY. Oh se PA Loree 
The evidence upon which plants are excluded from the native flora 
of regions in which they are found growing spontaneously, must in 
many cases be largely inferential. Some species there are of such 
world-wide notoriety that they may be branded as “ cosmopolitan 
weeds,” even when detected in the least suspicious places. As to 
others, direct testimony may sometimes be produced as to when, 
where and how they first obtained a foothold. But the records are 
too scanty, and the intrusion is usually too insidious for this to be 
often the case. The negative evidence of the absence of a species 
from every collection of plants is not conclusive, especially of com- 
mon weeds. In exploring a new field the well-known plants are the 
ones a collector is most likely to leave ungathered) Few are so 
thorough as to include in their sets purslane and pigweed, when 
most of the vegetation by which they are surrounded is still rare or 
new. It is the later gleaner who takes everything, and many of his 
additions are of plants his predecessors thought too common to 
gather. 
Often circumstantial evidence must be relied upon. The habitats 
of the suspected plant are to be examined, its history traced as far 
as possible, and the probabilities of its accidental origin and dis- 
persion considered. California is nota new country, if we date back 
- to its Spanish settlement, but the agencies by which plants are dis- 
seminated were few and sluggish in the days of the Missions, while 
in recent years their activity and multiplicity have been wonderfully 
increased. Railroads facilitate the transportation of produce of 
every kind from all parts of the country, and are likely to bring us 
most of the weeds and some of the indigenes of the regions through 
which their ramifications extend. The coming and spread of them 
should be recorded, and in their investigation the local observer 
may occupy himself with profit. 
_ The following notes are mostly confined to the four southermost 
counties of the State—San Diego, Orange, Los Angeles and San 
Bernardino—and relate more especially to the last named, in which 
my opportnnity for observations has been most extended. | __ 
mone the most widely dispersed of our naturalized pees the 
