10 BULLETIN 575, U. S. DEPARTMENT OE AGEICTJLTUBE. 



ACONITE. 



Plate IX is a picture of the ordinary aconite and is inserted in order 

 that it can be compared with the picture of the larkspur. Aconite, 

 as is well known, is a poisonous plant, but somewhat extensive experi- 

 mental work by the Department of Agriculture seems to have 

 demonstrated that it does not poison live stock upon the range. 

 It is important, therefore, that this plant should be distinguished 

 from larkspur, because in some localities it occurs in great abun- 

 dance, while larkspur is comparatively rare. This is true of certain 

 parts of the Yellowstone Park, where in some localities the swampy 

 regions are blue with aconite in the summer months, while the lark- 

 spur is only rarely met with. In other parts, however, like the region 

 between the Yellowstone Lake and the Grand Canyon, the larkspur 

 is very abundant and the aconite comparatively rare. 



Flowers of the aconite have the peculiar form from which the plant 

 has been known as "monkshood," and in most regions they are much 

 darker in color than the larkspurs. Generally speaking, in the 

 aconites of the West the flowers are of a very deep blue. There are 

 localities, however, in which the shades of color are much lighter, 

 almost the exact shades of the violet and purple that are more typical 

 of the larkspurs, while in other places the flowers are almost white. 



The roots of the tall larkspur are long, tough, and fibrous, while the 

 roots of aconite are short and tuberlike, with golden-yellow rootlets. 

 The stem of the tall larkspur is hollow, while the stem of the aconite 

 is pithy. 



LOW LARKSPUR. 



Plate XI is a typical picture of the low larkspur which is most 

 widely spread throughout the western ranges. This species is 

 Delphinium menziesii, probably the most destructive of the low 

 larkspurs, due to the fact that it occurs in such enormous masses. 

 There are regions in Colorado and Utah where many acres are almost 

 carpeted with these plants. They occur early in the spring, imme- 

 diately after the snow disappears, growing more rapidly than the 

 grasses, so that in some regions they seem for the time almost to 

 preempt the soil. These low larkspurs blossom comparatively early 

 in the season, and in Colorado Delphinium menziesii dries up and 

 disappears. not far from the 1st of July. Consequently the cases of 

 poisoning from low larkspurs occur almost entirely in the months of 

 May and June. 



It will be noted that the leaves of the low larkspurs are quite 

 different from those of the tall larkspurs, but are easily recognized 

 after one becomes fairly familiar with them. 



There is another low larkspur, occurring quite commonly in 

 Montana, the Delphinium hicolor, which is typical of somewhat lower 



