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



3. Psilostrophe sparsiflora (A. Gray) A. Nels., Biol. Soc. Wash. Proc. 



16: 23. 1903. 

 Riddellia tagetina var. sparsiflora A. Gray, Syn. Fl. I 2 : 318. 



1884. 

 Psilostrophe divaricata Rydb., North Amer. Fl. 34: 8. 1914. 

 Psilostrophe grandiflora Rydb., ibid. 



Apache County to eastern Mohave County and in Cochise County, 

 4,300 to 7,300 feet, dry mesas, slopes, and open pine forests, abundant 

 in places, May to September, type of P. divaricata from the Grand 

 Canyon (D. T. Allen in 1897), type of P. grandiflora from near Para- 

 dise, Cochise County (Blumer 1709). Utah, New Mexico, Arizona, 

 and Chihuahua. 



82. BAILEYA. Desert-marigold 



Low floccose-woolly herbs; leaves alternate, pinnatifid to entire; 

 heads solitary or cymose, long-peduncled, radiate, yellow; rays per- 

 sistent, becoming papery, reflexed in age; achenes striate, epappose. 



Key to the species 



1. Rays 5 to 7; heads loosely cymose toward the tips of the branches, relatively 

 small, the disk in flower 6 mm. thick or less 1. B. pauciradiata. 



1. Rays about 20 to 50; heads mostly solitary at the tips of the stem and branches, 

 larger, the disk in flower at least 10 mm. thick (2). 

 2. Stem leafy only at base or below the middle, the peduncles 10 to 20 cm. 



long 2. B. MULTIRADIATA. 



2. Stem leafy to above the middle or nearly to the apex, the peduncles 10 cm. 

 long or less 3. B. pleniradiata. 



1. Baileya pauciradiata Harv. and Gray in A. Gray, Amer. Acad. 



Arts and Sci. Mem. ser. 2, 4: 105. 1849. 

 Aztec to Yuma (Yuma County), 500 feet or lower, sandy deserts, 

 March to May (sometimes October). Southwestern Arizona, south- 

 eastern California, and adjacent Sonora and Baja California. 



2. Baileya multiradiata Harv. and Gray ex Torr. in Emory, Mil. 



Reconn. 144. 1848. 



Baileya multiradiata var. nudicaulis A. Gray, Syn. Fl. I 2 : 318. 



1884. 



Mohave County to Graham, Cochise, Santa Cruz, Pima, and Yuma 

 Counties, up to 5,000 feet, very common on sandy plains and mesas, 

 especially at roadsides, March to October. Western Texas to south- 

 ern Utah and Nevada, southeastern California, and Chihuahua. 



The large flower heads are very showy and this or a similar species 

 is sometimes cultivated in California for the flower trade. It is 

 stated that horses crop the heads, but fatal poisoning of sheep and 

 goats eating this plant on overgrazed ranges has been reported. 



3. Baileya pleniradiata Harv. and Gray in A. Gray, Amer. Acad. 



Arts and Sci. Mem. ser. 2, 4: 105. 1849. 



Baileya multiradiata pleniradiata Coville, Contrib. U. S. Natl. 



Herbarium 4: 133. 1893. 

 Baileya pleniradiata var. perennis A. Nels., Bot. Gaz. 47: 431. 



1909. 

 Baileya perennis Rydb., North Amer. Fl. 34: 10. 1914. 



Mohave County to Cochise, Pima, and Yuma Counties, 200 to 

 5,000 feet, plains and mesas, common in southwestern Arizona, 



