122 CORRIGIOLACEAE. 



Leaves straight, ascending ; spinules of sepals less than i mm. 



3. P. brevispina. 

 Flowers more or less clustered ; leaves much longer than the bracts. 



Plant low and diffuse, less than i dm. high ; calyx fully 3 mm. long. 



4. P. diffusa. 

 Plant taller, i dm. or more high; stem erect or ascending; calyx 2-2.5 mm. 



long. 

 Branches of the cymes ascending ; calyx about 2.5 mm. long ; sepals lanceolate, 



gradually acuminate. 5. P. Jamesii. 



Branches of the cymes divarcate ; calyx about 2 mm. long ; sepals oblong, 



abruptly acuminate. 6. P. Wardii. 



1. Paronychia pulvinata A. Gray. On exposed mountain tops from Wyo. 

 to Colo, and Utah. Alt. 11,000-14,000 ft. Cameron Pass; Mt. Garfield; 

 Gray's Peak; Pike's Peak trail; Massif de 1'Arapahoe; Berthoud Pass. 



2. Paronychia sessiliflora Nutt. On dry ridges from Sask. to Alb., Tex. 

 and Utah. Alt. 5000-8000 ft. Upper Larimer River. 



3. Paronychia brevispina (A. Nels.) Rydb. (P. sessiliflora brevispina A. 

 Nels.) On dry hills in Wyo. and Colo. Waldon, North Park. 



4. Paronychia diffusa A. Nels. On dry plains and mountains from S. D. 

 to Wyo., Kans. and Colo. Alt. 5000-13,000 ft. Castle Rock, near Golden ; 

 Gray's Peak; Pike's Peak trail; Table Rock. 



5. Paronychia Jamesii T. & G. On dry plains and mountains from Neb. 

 to Wyo., Tex. and N. M. ; also in Mex. Alt. 4000-10,000 ft. Ruxton Ridge; 

 Pike's Peak ; river flats east of Ft. Collins ; Horsetooth Mountain ; moun- 

 tains between Sunshine and Ward ; Boulder ; Larimer Co. ; Morrison ; 

 Meadow Park, Lyons ; Colorado City; Spring Canon; Ft. Collins; Horse- 

 tooth Mountain. 



6. Paronychia Wardii Rydb. On dry plains from Neb. to Colo., Kans. and 

 Tex. Alt. up to 7000 ft. Colorado City; Cheyenne Mountain. 



Family 48. ALLIONIACEAE Reichenb. FOUR-O'CLOCK FAMILY. 



Bracts distinct. i. ABRONIA. 



Bracts united. 



Fruit neither strongly tubercled nor winged. 



Fruit not ribbed ; involucre herbaceous, little if at all enlarging in fruit, not 



becoming membranous. 

 Stamens usually 5 ; involucres campanulate, not enlarged in fruit. 



2. QUAMOCLIDIOX. 



Stamens 3 ; involucre rotate, somewhat enlarged in fruit in the manner of 



the next genus, but not membranous. 3. ALLIONIELLA. 



Fruit ribbed ; involucre rotate, in fruit becoming much enlarged and mem- 

 branous. 4. ALLIONIA. 

 Fruit with two rows of strong tubercles on the back and surrounded by two 

 toothed inflexed wings. 5. WEDELIA. 



i. ABRONIA Juss. 



Fruit narrowly winged or crested ; wings or crests not completely encircling the 



fruit. 

 Fruit biturbinate, i. e., tapering at both ends, irregularly ridged or crested. 



i. A. fragrans. 

 Fruit turbinate or obpyramidal, i. c., almost truncate above, distinctly winged ; 



the wings very broad above. 

 Bracts broadly ovate or obovate, acute or obtusish. 



