798 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



throughout the United States; from South America or the Eastern 

 Hemisphere. 



Jimsonweed. The form with herbage and flowers purplish (D. 

 tatula) may also occur in Arizona. 



2. Datura quercifolia H. B. K., Nov. Gen. et Sp. 3: 7. 1818. 



Near Tombstone (Cochise County), Patagonia and Elgin (Santa 

 Cruz County), 4,000 to 5,000 feet, October. Texas to southern 

 Arizona and Mexico. 



3. Datura meteloides DC, Prodr. 13 *: 544. 1852. 



Navajo County to Mohave County, south to Cochise, Santa Cruz, 

 and Pima Counties, 1,000 to 6,500 feet, roadsides and along ditches 

 May to October. Colorado to Texas, Arizona, southern California 

 and Mexico. 



Sacred datura. With its very large, trumpet-shaped, pale lavender 

 flowers this plant is a conspicuous feature of the vegetation. It is 

 used by the Indians for various medicinal purposes, the seeds, it is 

 reported, being sometimes administered to prevent miscarriage. 



4. Datura discolor Bernh., Neues Jour. Pharm. Trommsd. 26: 149- 



1838. 

 Pinal, Maricopa, Cochise, Pima, and Yuma Counties, seldom above 

 2,000 feet, roadsides and waste ground, autumn. Southern Arizona, 

 southeastern California, and Mexico. 



9. NICOTIANA. Tobacco 



Plants herbaceous or (one species) arborescent; leaves sessile or 

 petioled, the blades entire or sinuate-margined; inflorescence terminal, 

 paniculate or racemelike; calyx 5-lobed; corolla tubular to salverform; 

 capsule apically dehiscent, 2- or 4-valved; seeds small, very numerous. 



The leaves of many of the species beside N. tabacum contain nicotine 

 and were smoked by the Indians. N. trigonophylla is still used for this 

 purpose, chiefly on ceremonial occasions. Animals usually avoid 

 these plants, but cases of poisoning in cattle, horses, and sheep have 

 been reported. Tree-tobacco (N. glauca) contains an alkaloid, ana- 

 basine, reported to be more efficacious than nicotine in killing certain 

 species of aphid. 



Key to the species 



1. Plant shrubby or arborescent; herbage glabrous and very glaucous; corolla 

 yellow, tubular-funnelform, 25 to 50 mm. long, densely pubescent exter- 

 nally, with a very short, erect limb; flowers diurnal; leaf margins entire or 



slightly undulate 1. N. glauca. 



1. Plants herbaceous, annual or (in N. trigonophylla) sometimes perennial and 

 suffrutescent; herbage pubescent or puberulent, viscid, not at all glaucous; 

 corolla white or greenish white, with a well-developed, more or less spread- 

 ing limb (2) . 

 2. Leaves mostly cordate- or auriculate-clasping, sessile or with short broad 

 petioles; corolla rather copiously pubescent on the whole external sur- 

 face, 15 to 25 mm. long; flowers diurnal 2. N. trigonophylla. 



2. Leaves not cordate or auriculate at base; corolla glabrous or very sparsely 

 pubescent externally with hairs mostly confined to the throat and limb; 

 flowers vespertine (3) . 

 3. Calyx lobes linear-lanceolate, very unequal, the longer ones in fruit equal- 

 ing or longer than the calyx tube; stem leaves mostly sessile, the blades 

 prevailingly ovate or lance-ovate; corolla 10 to 18 mm. long. 



3. N. CLEVELANDI. 



3. Calyx lobes deltoid, nearly equal, all much shorter than the calyx tube; 

 stem leaves mostly petioled, the blades prevailingly linear-lanceolate to 

 oblong-lanceolate; corolla 20 to 40 mm. long 4. N. attenuata. 



