THE DOGWOOD AND GUM 241 



The western dogwood is similarly an under tree, frequently of 

 Douglas fir, redwood, or western hemlock, and reaches its largest 

 size in the Douglas fir forests of the Puget Sound country, where it 

 may reach a height of 100 feet and a diameter of 2 feet, but is usually 

 from 40 to 60 feet tall and with a trunk diameter of from 8 to 12 

 inches. It probably reaches an age of from 150 to 250 years, is a 

 vigorous annual seeder of persistent vitality, and is found from 

 southern British Columbia near the coast, that is, the lower Fraser 

 River and Vancouver Island region, through Washington, Oregon 

 and Cahfomia to the San Jacinto Mountains and the western 

 slopes of the Sierra Nevadas. 



The dogwoods all have rather characteristically shaped and 

 veined leaves, and consequently considerable is known of their 

 geological history. Over 50 fossil forms have been described, and 

 the oldest kno\vn of these come from the Upper Cretaceous. A 

 dozen different forms have been recorded from the rocks of that 

 far off age, and the oldest of these occurrec^ in western Greenland 

 and in beds of approximately the same age along the Atlantic coast 

 of North America of that time, when the coast was somewhat 

 west of where it is today. Similar ancient dogwoods left their 

 leaves in the initial sandy deposits that were laid down by the 

 Upper Cretaceous sea that swept over our western plains country 

 from the Gulf of Mexico. 



Dogwood leaves continue to turn up throughout the Cretaceous 

 in Colorado, Wyoming, Montana, Vancouver Island and Green- 

 land, but none have thus far been found outside of North America 

 except for a single form recorded from supposed Upper Cretaceous 

 deposits in Spitzbergen. These facts suggest that America was 

 near the place of origin of the dogwood tribe. At least dogwoods do 

 not seem to have reached Europe until much later. What happened 

 in Asia in those far off days can only be surmised, since we know 

 scarcely anything of the later floral history of that vast area. 



During the first stage of the succeeding Tertiary period — the 

 Eocene, or dawn period of modern life — ^13 species of the dogwood 

 have been discovered. The bulk of these are American, but there 

 was a single form in France and 2 others are known from the late 



