Minnesota Plant Life. 



329 



scented flowers, abundant in two varieties in the tamarack 

 swamps of the state; the kidney-leafed violet, with leaves of a 

 broad kidney shape and longer than the flowering stem ; the 

 lance-leafed violet, with leaves shaped like those of the wil- 

 low. All these belong to the stemless group. Among the 

 stemmed forms are Nuttall's violet, a prairie variety, with elon- 

 gated, lance-shaped leaves ; the halberd-leafed violet, with 

 leaves shaped like arrow-heads and yellow flowers like those of 

 the preceding species. Here, also, is the common yellow violet 

 of the woods, with heart-shaped and kidney-shaped leaves and 

 hairy stems, usually solitary. Very similar to this is the smooth, 

 yellow violet, with narrower heart-shaped leaves, smooth stems 

 and foliage, and clustered growth. Related to these yellow- 

 flowered species is the Canada violet of rich woods, with its 

 violet or whitish flowers and heart-shaped leaves, and the very 

 similar striped violet, with cream-colored, white or blue flowers. 

 Both the latter have stems five to fifteen inches in height and 

 not tufted. The Labrador violet, with smaller heart-shaped 

 leaves and purple or white flowers, may be distinguished by its 

 tufted growth and its production of closed flowers later in the 

 season than the ordinary open ones. The sand violet is known 

 by the strongly notched, slender stipules of the leaves. The 

 flowers are of violet color, the stems are tufted and the leaves 

 are kidney-shaped or heart-shaped, on stems longer than their 

 blades. The long-spurred violet of the Isle Royale and Grand 

 Marais region may be recognized by the slender spur of the 

 flower, in length equaling or exceeding the petals. Besides 

 the native forms the common pansy has escaped from flower- 

 gardens in the southern part of the state and sometimes occurs 

 as a dooryard weed. 



Violets show in their two-sided flowers an adaptation similar 

 to that seen lower in the series in the two-sided flowers of the 

 pulse family and of the larkspurs, or, still lower, in the flowers 

 of orchids. 



Prickly-pears. The twenty fourth order includes but a single 

 family, the cacti, to which belong three species of prickly-pears 

 and the purple cactus — rock-plants of southern Minnesota. 

 The cactus family is a very extraordinary group, in which stems 

 have become fleshy and consolidated, while leaves have been 



