286 GEOGKAPHICAL DISTRIBUTION OF PLANTS. 



Douglas, nourishes some of the largest sugar maples in North 

 America. 



A. rubrum, red or swamp maple, ranges southwards, accord- 

 ing to Dr. Gray, to Florida, and round the whole Gulf of Mexico 

 to northern Texas ; but some of the southern forms, he says ? 

 would probably be considered by European botanists to be 

 specifically distinct from the northern tree. It grows in Nova 

 Scotia, throughout Canada, westward to Lake Winipeg and the 

 Rocky Mountains on the 52nd or 53rd parallel, and also crosses 

 that chain to the head waters of the Columbia. 



A. pennsylvanicum, striped maple, or moose wood, comes 

 down along the coast to Boston, and follows the mountains 

 from Pennsylvania to the borders of Georgia, to which Dr. Gray 

 has traced it. It grows also in Kentucky, and was seen by us 

 on the banks of the Winipeg, where it has more the character 

 of a flexible willow than of a tree. A. macrophyllum is confined 

 to the mountainous country on the Pacific up to the 50th parallel, 

 and is one of the most graceful trees, rising to the height of 

 ninety feet, with a circumference of sixteen. A. dasycarpum, 

 white or silver maple, is a fine large ornamental tree, well known 

 in the United States. It is found on Lake Huron, but does 

 not appear to rise northwards out of the St. Lawrence basin. 

 Good sugar is made from the juice of this tree. 



Negundo fraxinifolium or aceroides, ash-leaved maple, does 

 not, to Dr. Gray's knowledge, grow wild in New England. It 

 abounds in Pennsylvania, and extends westwards to western 

 Texas and the Rocky Mountains, growing at the high elevation 

 of 6,000 or 7,000 feet near Santa Fe and the Pawnee Fork, 

 according to Lieut. Abert. It terminates northwards about 

 the 54th parallel on the banks of the Saskatchewan, and is the 

 tree which yields most of the sugar made in Rupert's Land. 

 Though this product varies much with the skill of the operator, 

 the kind obtained from the juice of this tree is generally of a 

 darker colour than that which the true sugar maple yields. 



Ampelideje. — Ampelopsis quinquefolia, Virginia creeper, 

 or American ivy, extends northwards to Lake Winipeg, and is 

 a great ornament to the protruding rocks over which it creeps. 



