128 OUTLINE OF PLANT GEOGRAPHY 



developed to a remarkable degree, but a great variety of broad- 

 leaved evergreens are found, especially in the southern part of 

 the area. Evergreen oaks, laurels, huckleberries, barberries, and 

 other less familiar genera, abound in the Californian flora. 



The mild climate and a very heavy rainfall result in a luxuriant 

 forest as far north as about 60° in coastal Alaska, corresponding 

 in latitude to northern Labrador and the southern tip of Green- 

 land, regions of arctic cold and destitute of any forest vegetation. 



A feature of the Pacific coast is an extraordinary development 

 of the giant kelps, these huge brown sea-weeds growing in profu- 

 sion on the rocky shores from Alaska to the Mexican boundary, 

 being especially abundant in Central California. 



The best known of the giant kelps is the great bladder-kelp 

 (Macrocystis pyrifera), which also is found in the colder waters of 

 the southern hemisphere. Other kelps reaching a great size are 

 species of Alaria, Egregia, Nereocystis and Pelagophycus. The 

 two latter may reach a length of 100 feet or more, and grow in 

 deep water, the huge leaves being buoyed up by a single globular 

 float, which in Pelagophycus is as large as a coconut. 



The majority of these kelps are peculiar to the Pacific Coast 

 of North America, and constitute one of the most remarkable 

 features of the Pacific Coast vegetation. 1 



The typical coastal flora of southern Alaska is well developed 

 about Sitka. The forest is very dense, made up mostly of two 

 species, the Sitka spruce (Picea Sitchensis) and a hemlock 

 (Tsuga Mertensiana). A third species, the Alaska cedar (Cham- 

 aecyparis Xootkatensis), has been largely exterminated, as its 

 wood is especially prized for making the great dugout canoes, 

 and for wood carvings. 



While the trees of this forest do not attain the great size found 

 further south, still they are fine large trees, the spruces often 

 attaining a height of over 100 feet, with a diameter, occasionally, 

 of 6 to 8 feet, The forest floor is covered with a dense carpet 

 of mosses, which also cover every stump and fallen log. Among 

 the mosses grow the usual low evergreen species of the northern 

 forests, e. g., Pyrola, Linnaea, dwarf cornel, various species of 

 Lycopodium, and ferns, etc. The abundant and constant mois- 



1 The algae of the Alaska coast are decribed at some length by Harshberger, 

 loc. cit., p. 5^7. 



