FLORA OF THE SANTA BARBARA ISLANDS. 223 



31alacothrix Coulteri, which is, however, not a Coast Range 

 plant. This plant, on the eastern end of Santa Cruz Isl- 

 and, is found in its mainland form, and growing with it 

 plants varying toward M. insularis, which, in exposed 

 situations, might easily become M. squalida or indecora. 



A species which can flourish in the Sierra Nevada moun- 

 tains, withstand the extreme summer heat of the cen- 

 tral valleys, and also grow amongst the fogs of the Coast 

 Kange and adjacent islands, must reflect somewhat in its 

 characters the very diverse conditions under which it ex- 

 ists. The extreme differences of climate that are found 

 within a few miles distance make the flora of California a 

 flora of variable species, a flora that should be studied in 

 the field or with abundant material from many localities. 

 The division of the year into wet and dry seasons in- 

 duces a form of variation which it may be not out 

 of place to notice, especially as it has some connection with 

 insular plants; it is that many perennial species undoubt- 

 edly also persist as annuals if they are able to mature their 

 seed before the summer's drought kills them. This pecu- 

 liarity is alluded to by Dr. Engelman in the Botanical Ga- 

 zette, Vol. VI, 235, with reference to Esdischoltzia. 



The great extent of coast line of the islands, Santa Cruz 

 having over fifty miles and Santa Rosa more than forty, 

 compared with their area, affords a large habitat for a 

 maritime flora, and plants most abundant in the vicinity 

 of salt water, form a large proportion of the insular flora. 

 This is more noticeable on the sloping hills of Santa Rosa 

 than on the bold and rocky shores of Santa Cruz, and ac- 

 counts for the seemingly great preponderance of such sea- 

 shore plants as Esclischoltzia , Cotyledon, Abronia, Mesembri- 

 anthemiim, and others. 



The insular floras should be compared with those of the 

 neighboring shore and coast range rather than with that of 



2d Seb. Vol. I. (16) Issued Oc'.ober 11, 1888. 



