FLOWERING PLANTS AND FERNS OF ARIZONA 995 



6. Pappus of 2 to 4 smooth or antrorse-hispidulous awns (7). 



7. Pappus of 2 or 3 smooth divergent awns; ligules about 1 mm. long. 



6. P. LI. VI FOLIA. 



7. Pappus of 2 to 4 antrorse-hispidulous awns; ligules 4 to 6 mm. 

 long 8. P. FILIPES. 



4. Pappus various, but not of 2 to 6 rigid subulate awns (8). 



8. Plants perennial, with a woody rootstock, low, 10 to 20 cm. high, leafy 

 only toward the base, with long naked peduncles; leaves with 1 to 3 

 pairs of bristles at base; phyllaries 12 to 15; pappus of the disk flowers 

 of 20 to 40 unequal bristles, that of the ray flowers of 2 bristles and 



sometimes a few squamellae 7. P. loxgipes. 



8. Plants annual (9). 



9. Phyllaries 5; pappus of 1 to 4 subulate awns and sometimes a few 



squamellae, or reduced to a crown of squamellae 8. P. filipes. 



9. Phyllaries 8 to 10 (10). 



10. Heads rather crowded, sessile or peduncled, not obviously surpassing 

 the leaves (11). 

 11. Leaves not dilated at base; pappus normally of 12 to 18 bristles, 

 sometimes reduced to a crown 9. P. papposa. 



11. Leaves dilated at base; pappus a crown of squamellae, with or 



without 1 or 2 awns 10. P. axgustifolia. 



10. Heads mostly solitary at the tips of the branches and in the axils 

 and forks of the stem, the peduncles usually considerably sur- 

 passing the leaves (12). 



12. Pappus in the ray flowers of 2 to 5 slender awns or bristles, in 



the disk flowers of numerous bristles at least half as long as 



the disk corollas 11. P. palmert. 



12. Pappus in the ray flowers of 1 or 2 slender awns or bristles, in 

 the disk flowers of numerous short bristles or reduced to a 

 crown 12. P. rtjsbyi. 



1. Pectis prostrata Cav., Icon. PL 4: 12. 1797. 



Mountains of Cochise and Pima Counties, 4,000 to 6,000 feet, 

 sandy plains and dry slopes, August to October. Western Texas to 

 southeastern Arizona, south to northern South America; also in 

 Florida, Cuba, and Jamaica. 



2. Pectis cylindrica (Fernald) Rydb., North Amer. Fl. 34: 198. 1916. 



Pectis prostrata var. cylindrica Fernald, Amer. Acad. Arts and 

 Sci. Proc. 33: 68. 1897. 



Beaver Creek (eastern Yavapai County), Sacaton and Eloy (Pinal 

 County), San Bernardino Ranch (Cochise County), Duquesne (Santa 

 Cruz County), 1,300 to 5,000 feet, sandy-gravelly plains and mesas, 

 May to September. New Mexico, Arizona, and Sonora. 



3. Pectis urceolata (Fernald) Rydb., North Amer. FL 34: 197. 1916. 



Pectis prostrata var. urceolata Fernald, Amer. Acad. Arts and 

 Sci. Proc, 33: 68. 1897. 



Gila, Cochise, and Santa Cruz Counties, 4,000 to 5,000 feet, August 

 and September. New Mexico, southeastern Arizona, and Chihuahua. 



It is doubtful whether P. urceolata and P. cylindrica are specifically 

 distinct from P. prostrata. Two of the few collections examined 

 (Smart, Santa Cruz, August 10, 1867, Peebles et al., 5566, from near 

 Nogales) have only 3 phyllaries as in P. cylindrica, but these are puber- 

 ulous as in P. urceolata, which normally has 5. 



4. Pectis imberbis A. Gray, PL Wright. 2: 70. 1853. 

 Southwestern Cochise County and Santa Cruz County, 4,000 to 



5,500 feet, August to October, type from "on the Sonoita," probably 

 in southwestern Cochise County (Wright 1399). Southwestern 

 Arizona, Sonora, and Chihuahua. 



