STOCK-POISONING PLANTS OF THE RANGE. 9 



wild geranium, which in many places grows abundantly with the 

 tall larkspur, but the different habit of the plant makes it compara- 

 tively easy to distinguish between them. 



It is more difficult to distinguish between aconite and larkspur, 

 because the leaves of the aconite are almost identical in form with 

 those of the larkspur, and the habit of the plant is similar. In 

 Plate IX is given a picture of the ordinary aconite in which this 

 similarity will be noted. The leaves of aconite have shorter petioles 

 (leaf stalks) than those of larkspur. 



Species of tall larkspurs are found in all the mountain ranges of 

 the West at high elevations, growing up as high as the timber line. 

 Sometimes they are found as scattered clumps of plants, but fre- 

 quently they grow in large masses. 



Plate VII shows the leaf, flower, and seed pod of the tall larkspur 

 which is most common in Montana and adjoining States, known to 

 botanists as Delphinium cucullatum. This does not ordinarily grow 

 to any considerable height— perhaps not more than 4 feet — and the 

 flower is less conspicuous than in most of the tall larkspurs. The 

 color is ordinarily described as a grayish purple, due to the fact 

 that there is considerable white in connection with the violet-purple 

 shades of the corolla. This plant is responsible for most of the 

 deaths of cattle by larkspur in Montana. Plate VIII shows the tall 

 larkspur of the Pacific coast region; it has a much more conspicuous 

 and beautiful flower than Delphinium, cucullatum. 



Delphinium barbeyi is perhaps the most widely distributed species 

 of the tall larkspurs and is the plant which causes the greater part 

 of the tall-larkspur losses in Colorado, Utah, and some other locali- 

 ties. Plate X shows the plant as it grows in the midst of other 

 plants in the high mountains of Colorado. In this picture it is 

 growing in connection with aconite, Veratrum, and some other weeds. 



In most cases the tall larkspurs blossom during the summer 

 months and do not die down until they are broken by the snows 

 of the early fall. The exact time of blossoming differs with the 

 species and with the places in which they occur. In the mountains 

 of Colorado the blossoming period is ordinarily in July, and the 

 seeds are formed in August, after which the plant commences to 

 dry up. The leaves of the tall larkspurs lose their poisonous proper- 

 ties after blossoming, so that in most localities the cases of poison- 

 ing from these plants occur in the spring or early summer. In the 

 case of some species, however, especially in localities where the snow- 

 fall is heavy and remains late in the season, in certain parts of the 

 Sierras, the period of blossoming continues into the late summer, so 

 that poisoning cases may occur at any time during the season. 



The seeds of the tall larkspurs are very poisonous, but they are 

 not eaten to any extent, by cattle. 



106738°— Bull. 575—18 2 



