OF ARTS AND SCIENCES. IQo 



VI. 



BOTANICAL CONTRIBUTIONS. 



By Sekeno Watson. 



Presented, Oct. 12, 1875. 



I. On the Flora of Guadalupe Island, Lower California. 



The Island of Guadalupe is in lat. 29° north, about one hundred 

 miles from the coast of Lower California, and two hundred and thirty 

 west of south from the town of San Diego, which is near the southern 

 line of California. It is twenty-six miles in length in a north and 

 south direction, with an average breadth of ten miles, and is traversed 

 by a mountain ridge, the central peak (Mount Aug.usta) having an 

 elevation of 3900 feet above the level of the sea. From this point 

 the nearest mainland is visible. The sides of the ridi^e are exceed- 

 ingly rough and broken, cut up by numerous deep and rocky canons, 

 and even the more level surfaces are described as usually covered by 

 rocks of every size and form. The rocks are volcanic, and several 

 extinct craters still exist. 



The island lies within the great ocean current which flows from the 

 peninsula of Alaska down our western coast, the continuation of what 

 is known as the Japanese Gulf-stream, and in the zone of the north- 

 west trade-winds. Fogs are very prevalent, especially in the winter 

 months (from November to February), when they are driven by the 

 winds over the crest of the island, covering all the northern end and 

 filling the upper portions of the caiions, while the lower canons and 

 the southern extremity of the island remain clear and warm. These 

 winter winds from the north-west are described as strong and cold, 

 sometimes extremely so, an instance of which occurred during Decem- 

 ber, 1874, when ice an inch in thickness was formed in the middle of 

 the island, accompanied by two inches of snow, which was followed by 

 hail and five days of cold rain. In summer these winds have less 

 force, though still brisk and chilly for much of the time; and tlie fogs, 

 instead of being cari-ied over the central ridge, are driven around the 

 northern end, and by eddy-winds are borne into the lower caiions of 



