320 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



Counties), 6,000 feet or lower, open flats, valley floors, and gentle 

 foothill slopes, May. Southern New Mexico and southern Arizona. 



The Arizona plants have pale blue or lavender flowers rather than 

 the whitish or cream-colored flowers of the type. This larkspur, a 

 relative of D. camporum Greene which ranges to the northeast of this 

 area, is notable for its deeply notched and white-pilose petals and 

 long, often geniculate, spurs. 



2. Delphinium scaposum Greene, Bot. Gaz. 6: 156. 1881. 

 Coconino, Mohave, Yavapai, Gila, Maricopa, Pinal, and Pima 



Counties, 5,000 feet (rarely 7,000 feet) or lower, locally frequent on 

 open deserts and gravelly mesas, March to May. Southwestern 

 Colorado to southern Nevada, New Mexico, and Arizona. 



The typically scapose habit and deep royal-blue flowers (except in 

 northern Arizona plants) are distinctive. Plants of the Colorado 

 River and Plateau drainages have lighter blue flowers, more diffuse 

 racemes, and follicles 18 to 20 mm. long, as compared with 10 to 13 

 mm. long in the type. This larkspur is used by the Hopi Indians, who 

 call it "tcoro'si." It is reported that they grind the flowers with corn 

 to make a blue meal, "blue pollen," for the flute altar, and also use 

 the plant as an emetic in one of their rituals. At least in portions of 

 its range this species is known to be poisonous to cattle. 



3. Delphinium pinetorum Tidestrom, Biol. Soc. Wash. Proc. 26: 121. 



1913. 

 Defiance Plateau (Apache County), Navajo Mountain, Kaibab 

 Plateau, and Mogollon Mesa (Coconino County), 6,000 to 8,600 feet, 

 yellow pine forests, type from the Kaibab Plateau (Tidestrom 2375). 

 Southern Utah to central Arizona. 



4. Delphinium amabile Tidestrom, Contrib. U. S. Natl. Herbarium 



25: 207. 1925. 



Delphinium coelestinum Rydb., Torrey Bot. Club Bui. 39: 320. 

 1912. NotFranchet. 



Coconino, Mohave, Maricopa, and Pima Counties, 3,500 feet or 

 lower, rocky knolls and desert mesas, March to April. Southwestern 

 Utah and Arizona to southern California. 



This is the most xerophytic of North American larkspurs. The 

 reduction in vegetative parts enables the plants to withstand withering 

 heat or prolonged droughts. The species has developed many local 

 races. The range in Arizona, as given above, is that of the typical 

 form. The subspecies apachense (Eastw.) Ewan (D. apachense Eastw.) 

 occurs in Gila, Maricopa, Pinal, and Pima Counties, 5,000 feet or 

 lower, February to April, commoner than the typical form. It has 

 sinuses of the lower petals 2 to 2.5 mm. deep, the lobes distally spread- 

 ing, leaves rather conspicuous at flowering time, flowers clear sky blue, 

 in loose racemes; whereas, in typical D. amabile, the sinuses of the 

 lower petals are 1.5 to 2 mm. deep, the lobes not noticeably spreading, 

 leaves withering, not noticeable at flowering time, flowers mostly deep 

 blue, in moderately dense racemes. The size and form of the leaves 

 vary greatly in the subspecies, in response to varying ecologic factors. 



