Barbey larkspur, a perennial herb, is one of the most characteris- 

 tic, abundant, and widely distributed of the tall larkspurs. It is 

 typically a plant of the higher mountains, ranging mostly from 

 about 8,000 feet up to timber line, but occasionally as low as 6,000 

 feet toward the northwestern limits of its range. The species ap- 

 pears to be confined to four States : Wyoming, Colorado, Utah, and 

 Idaho. Large patches of this tall larkspur may be found growing 

 abundantly in canyons and on moist, well-drained soils. Probably 

 the most serious cattle losses from tall-larkspur poisoning through- 

 out its known western range is caused by Barbey larkspur, and the 

 species has been the basis of much experimental work as representa- 

 tive of tall-larkspur poisoning. 



The stored food in the large and deep woody taproot of this and 

 other tall larkspurs facilitates the rapid growth of leafy stems early 

 in the spring before many edible but harmless plants have made an 

 appreciable start. Growth of as much as 1 to 2 feet in May has 

 been reported, but the rapidity of development varies greatly accord- 

 ing to the altitude and moisture and temperature conditions. The 

 large leaves are more poisonous than the stems and are most toxic 

 when the plants are starting spring growth. Their poisonous prop- 

 erties decrease when the flowers and seeds mature in July and 

 August. In fact, cattle often graze the palatable green leaves that 

 persist after the plant has seeded without harmful effect. 1 The seeds 

 of this species are very poisonous and have occasionally caused some 

 losses. Although the roots also contain the toxic principles, their 

 woodiness, and deep underground habit of growth render them prac- 

 tically inaccessible to cattle. Barbey larkspur does not die down 

 after setting seed; the leaves remain palatable until killed by frost. 



Although Barbey larkspur, if eaten in sufficiently large quantities 

 and within a comparatively short time, may cause sheep poisoning, 

 range fatalities seldom, if ever, occur, except possibly under badly 

 overgrazed or other very abnormal conditions. Horses may be 

 poisoned experimentally by this species but, under range conditions, 

 this class of livestock apparently never eats enough of this larkspur 

 to be injured. In most instances infested ranges may be used with 

 safety for pasturage of sheep and horses. 



Although it is easy to distinguish Barbey larkspur after it blossoms because 

 no other plant in its habitat has similar flowers, these plants, in the early 

 stages of leaf and stem growth, are often confused with sticky geranium 

 (Geranium tftscosissimum) , a harmless, widely distributed and common range 

 plant, and also with monkshoods, particularly Columbia monkshood (Aconitum 

 columbianum) . The leaves of sticky geranium are mostly basal and long- 

 stalked those that do occur on the stem being paired while the leaves of 

 Barbey larkspur all come from the stem, are not paired, and are shorter- 

 stalked. The leaves of monkshood are very similar in shape, size, and arrange- 

 ment to those of Barbey larkspur, but are somewhat shorter-stalked ; the stems 

 of monkshood are pithy as a rule, while those of larkspur are usually hollow ; 

 the roots of monkshood are tuberous and often clustered near the soil surface, 

 while those of Barbey larkspur are enlarged, woody, and deep; the well-devel- 

 oped hood of the monkshood flower and the marked spur of the larkspur are 

 very distinctive. 



1 Marsh, C. D., Clawson, A. B., and Marsh, H. LARKSPUR OR "POISON WEED." U. S. 

 Dept. Agr. Farmers' Bull. 988, rev., 13 pp., illus. 1934. Supersedes Bull. 531. 



Clawson, A. B. ADDITIONAL INFORMATION CONCERNING LARKSPUR POISONING. U. S. 

 Dept. Agr., Supplement to Farmers' Bull. 988, 2 pp. 1933. 



