Vesicular in the Californian plant with which I am acquainted. This is not evident _ 
206 Naturalized Plants. [ZOE 
‘But not only are these common genera, but, descending to spe- 
cies, we find no small number which are equally at home in the two 
countries. The most important are included in the subjoined 
TABLE OF SPECIES. 
Myosurus aristatus, Gilia gracilis, 
Sisymbrium canescens, Gilia pusilla, 
Pentacena ramosissima, Polemonium micranthum, 
Elatine Americana, Phacelia circinata, 
Trifolium Macrei, Plagiobothrys rufescens, 
Trifolium microdon, Pectocarya linearis, 
Hosackia subpinnata, Pectocarya pusilla, 
Prosopis julifiora, Mimulus luteus, 
Acena trifida, Plantago Patagonica, 
Tillea minima, Plantago hirtella, 
(@nothera dentata, Allionia incarnata, 
Bowlesia lobata, Parietaria debilis, 
Valerianella samolifolia, Callitriche marginata, 
Baccharis glutinosa, Oxytheca dendroidea, 
Amblyopappus pusillus, Lastarriea Chilensis, 
Madia sativa, Lilea subulata,* 
Soliva sessilis, _ Scirpus Tatora, 
Specularia biflora, Muhlenbergia debilis. 
Microcala quadrangularis, 
These plants are somewhat less exclusively western than are those 
_in the former list; still they will be seen to be for the most part dis- 
tinctly accidental. In this State a very few of them are confined to 
the vicinity of its northern boundary, but every remove southward 
_ adds increasing numbers, even till the southern line is reached, over 
which some species barely pass. Were we to extend our survey 
still farther south, the list might be materially increased. They are 
a part indeed of what we call the Mexican element in our flora, which 
is itself but a section of the great Cordilleran flora which follows 
_ along the backbone of the two continents. _ | 
_ What may have been its origin and what its past migrations along 
the western flanks of this vast mountain chain is beyond our purpose © 
here to inquire. It is enough to point out that so many species are 
_common to both Chili and California, that the presence in either 
_ * Lileea is described as having “ thin, grass-like ” leaves, but they are terete and 
ig” 
in dried specimens, so that the description may easily be erroneous. Otherwise — 
our plant is distinct, In either case the generic character must beamended. 
: i 
