FLOWERING PLANTS AND FERNS OF ARIZONA 627 



25. Capsule cvlindric or clavate, distinctly pediceled: Subgenus Chylismia 



(31). 



31. Leaves orbicular-cordate, well distributed along the stem, not at all 



pinnatifid, commonly glandular-pubescent; plants rather coarse; 



flowers yellow, becoming bright red in age; anthers glabrous; 



capsules on rather short pedicels, coarse-cylindric. 



3l. O. CARDIOPHYLLA. 



31. Leaves ovate, oblong, or lanceolate, mostly near the base of the 



plant, commonly pinnatifid (32). 



32. Capsules linear, elongate, usually more than 2 cm. long (33). 



33. Stems slender, commonly freely branched above; pedicels 



capillary, 10 to 25 mm. long; capsules linear, 1.5 to 3.5 cm. 



long; anthers glabrous in some forms; petals 1.5 to 9 mm. 



long 34. O. MULTIJUGA. 



33. Stems coarse, commonly branched only near the base; pedicels 



short, usually 3 to 15 mm. long; capsules linear, widely 



spreading. 2 to 9 cm. long; anthers hairy (34). 



34. Petals bright yellow, 12 to 15 mm. long; stem usually with 



conspicuous spreading hairs, especially near the base; 



sepals pilose; capsules 5 to 9 cm. long, 2 to 3 mm. thick; 



hypanthium with a swelling within on each rib at the 



upper edge of the pubescent portion 32. O. brevipes. 



34. Petals pale yellow, 8 to 12 mm. long; stem ashy-strigose, often 



without conspicuous spreading hairs; sepals strigulose to 



subglabrous; capsules 2 to 5 cm. long, 1 to 2 mm. thick; 



hypanthium without inner swellings __ 33. O. pallidula. 



32. Capsules somewhat clavate, usually less than 2 cm. long (35). 



35. Branches in well-developed plants capillary and arising freely 



throughout the plant; capsules 3 to 9 mm. long; anthers 



oblong to linear-oblong, glabrous; style not exceeding the 



petals; petals 3 to 7 mm. long 37. O. parryi. 



35. Branches in well-developed plants few to several and arising 

 at base of the plant only, not capillary; capsules 10 to 25 

 mm. long; anthers linear, with scattering white hairs; style 

 exceeding the petals (36). 

 36. Stems slender; flowers few, not crowded; leaves ovate, sub- 

 entire; petals usually less than 4 mm. long. 



35. O. SCAPOIDEA. 



36. Stems somewhat coarse; flowers crowded in close terminal 



clusters; leaves usually pinnatifid; petals 4 to 7 mm 



long 36. O. CLAVAEFORMIS' 



1. Oenothera hookeri Torr. and Gray, FL North Amer. 1: 493. 1840. 



Onagra hookeri Small, Torrey Bot. Club Bui. 23: 171. 1896. 



Two forms occur in Arizona, both growing in damp places. The 

 first, var. irrigua (Woot. and Standi.) Gates (O. irrigua Woot. and 

 Standi.), characterized by stems 1 to 2 m. tall, the pubescence mostly 

 closely appressed and ashy, the sepals not papillate at base of the 

 hairs, and the sepal tips 4 to 5 mm. long, has been collected in Navajo 

 and Coconino Counties, about 5,000 feet. It ranges from eastern 

 Utah and southwestern Colorado to New Mexico, Arizona, and 

 Chihuahua. The second form, var. hirsutissima (A. Gray) Munz 

 (0. biennis var. hirsutissima A. Gray, 0. hirsutissima Rydb.) char- 

 acterized by stems usually less than 1 m. high, with long divergent 

 hairs throughout, the sepals papillose at base of the long hairs, and 

 the sepal tips 2 to 3.5 mm. long, is found from Navajo and Coconino 

 Counties south to Cochise and Pima Counties, 5,000 to 9,500 feet, 

 July to October. It occurs also in New Mexico and Chihuahua. 

 These varieties intergrade with each other and with other forms of 

 0. hookeri 



