No. 388.] VACATION NOTES. 309 
be expected, this is reflected in its remarkably rich and interest- 
ing flora, which offers a most attractive field to the student of 
geographical distribution of plants. The state extends over 
ten degrees of latitude, with a coast line of over 1000 miles, 
and its highest mountains rise 15,000 feet above sea level. 
There are regions like the Mojave desert and Death valley 
which are absolute deserts, while in the northern coast ranges 
there are points where the annual rainfall probably exceeds 100 
inches, and the forests of giant redwoods rival the jungles of 
the tropics in the rank luxuriance of their vegetation. 
The great barrier of the Sierra Nevada and the even tem- 
perature of the ocean waters, due to the Japan current, combine 
to give the whole state a far more equable climate than is found 
elsewhere in the United States; and in the lowlands, winter, 
as we know it in the eastern states, does not exist, but instead 
the year is divided into two sharply marked seasons, the wet 
and the dry, of approximately equal length in the central part 
of the state. 
Besides these great climatic differences, which have pro- 
foundly influenced the native flora, the peculiar topography of 
California has also been an important factor in determining the 
origin of many of the plants. Direct communication with the 
eastern half of the continent is prevented by the great moun- 
tain barrier of the Sierra, and the mountains and deserts of the 
Rocky mountain area. It is only on the north and south that 
there is free communication with the neighboring regions, and 
we find, in consequence, a curious mingling of northern and 
southern plants, with an almost complete absence of peculiarly 
eastern American types. 
The continuous ranges of mountains extending into British 
Columbia and Alaska offer an easy road for many northern 
plants, which are equally at home in the coast ranges and Sierra 
Nevada, and in Canada and Alaska. With the rapid diminution 
in the rainfall south, most of these finally disappear, and are 
quite absent from the southern part of the state. Most of 
these northern genera, ¢.g., Trillium, Claytonia, Erythronium, 
and others, are found both in Asia and northeastern America ; 
but there are several Asiatic types which do not reach Atlantic 
