492 ONAGRACE.E. CEnothera. 



§ 1. Stigma cruciately i-jmrted, the lobes mostly elongated: tube of the calyx 

 much 'produced, linear, cylindrical, or somewhat A-angled, slightly dilated at 

 the summit : ^-'ctoZs mostly obovate or ohcordate {never lilac or purple) : 

 stamens scarcely unequal, often a little declined: anthers linear or linear-ob- 

 long, fixed near the middle, versatile : ccqjsules thick and coriaceous or some- 

 what ligneous. — Eu(enothp:ra. 



* Annual or biennial caulescent herbs : flowers {mostly large) erect before ex-pan. 

 sion, nocturnal, fugacious, yellow, usually turning to rose-color or violet in 

 fading : capsule coriaceous, sessile, more or less cylindrical or oblong-conic, 4- 

 ribbed, somewhat A-sided : seeds very numerous, arid arranged in two rows iii 

 each cell, nearly horizontal or ascending. — Onagra, Tourr,. (CEnothera & On- 

 agra, Spach.) 



1. CE. biennis (Linn.) : stem erect, mostly simple, usually hirsute ; leaves 

 ovate-lanceolate, repandly denticulate, acute, more or less pubescent ; flowers 

 in a terminal somewhat leafy spike ; tube of the cah'x much longer than 

 the ovary, and from one-half to 2-3 times longer than the segments ; 

 stamens slightly declined ; capsules oblong, slightly tapering above, obscurely 

 4-sided or almost terete; the valves 1-ribbed. — Onagra vulgaris & chry- 

 santha, Spach, I. c. 



a. vulgaris : petals a little longer than the stamens, slightly obcordate. — 

 CE. biennis, Linn. ! spec. 1. p. 346 ,• Michx. ! fl. 1. p. 224 ,- Engl. bot. t. 

 1534 ; DC! prodr. 3. p. 46 ,- Hoolc. ! fl.. Bor.-Am. 1. p. 209. CE. gauroi- 

 des, Hornem. hort. Hafn. 



p. muricata : petals a little longer than the stamens ; stem and ovaries 

 strigose-hirsute. — CE. muricata, Murr. in comm. Goett. 6. t. 1 ; Pursh, I. c. ; 

 FL Dan. t. 1752 ,• DC. I. c. 



y. grandiflora : petals large, much longer than the stamens, rather deeply 

 obcordate. — CE. gi-andiflora. Ait. Kew. {ed. 1.) 2. p. 2 ; Bot. mag. t. 2048. 

 CE. suaveolens, Desf. cat. (E. Lamarkiana, Seringe, in DC. I. c. 



d. parviflora : petals small, about the length of the stamens ; tube of the 

 calyx 2-3 times the length of the segments ; ovaries slightly hirsute. — CE. 

 parviflora, Linn..' spec. (ed. 2.) 1. p. 492. 



e. cruciata : petals (abortive) linear-oblong, shorter than the stamens; 

 tube of the calyx 2-3 times the length of the segments ; capsules nearly 

 glabrous. — CE. cruciata, Nutt. ! in DC. I. c. (under CE. parviflora.) 



^. canescens : petals longer than the stamens : stem and leaves canescently 

 hairy ; capsules canescent. 



Throughout N. America from lat. 56° to Florida ! Arkansas ! and Oregon ! 

 and naturalized in Europe. June-Aug. — Stem 1-5 feet high. Flowers 

 mostly pale yellow. — Many other varieties of this common and variable 

 species might be given : certainly none of them deserve the rank of species. — 

 Evening Primrose. 



2. CE. bifrons (Don) : pubescent ; stem erect, often branching above ; 

 leaves oblong or ovate, the upper ones short, closely sessile and somewhat 

 cordate, denticulate ; spikes elongated ; bracts ovate-cordate ; tube of the 

 calyx very slender, much longer than the segments and many times longer 

 than the slightlj^ hairy ovary ; petals (rather large) entire, about the length 

 of the stamens ; capsules prismatic-cylindrical, nearly glabrous. — Don, in 

 Brit.fl. gard. {ser. 2) t. 386; Hook.! bot. mag. t. 3764. CE. heterophylla, 

 Spach, Onagr. p. 28 ? 



Texas, Drummond ! — This species is allied to CE. biennis, but appears to 



