180 EVENING PRIMROSE FAMILY. 



4. LUDWIGIA. Stamens as many as the lobes of the calyx and cells of the pod, almost 



always 4. Petals 4, often small, or none. 



5. CLARKIA. Calyx tube barely continued beyond the ovary into a very short, funnel- 



form cup. Petals broad, wedge-shaped or rhombic, sometimes 8-lobed, raised on a 

 slender claw. Stamens 8, with slender filaments, the alternate ones shorter ; anthers 

 carved or coiled after opening, those of the short stamens much smaller, or deformed 

 and sterile. Stigmas 4, oval or oblopg. Pod linear and tapering upwards, 4-sided. 

 Flowers never yellow. 



++ ++ Flowers regular and symmetrical; calyx tube extended more or less beyond the 

 ovary, the lobes mostly reflexed; petals 4. 



6. EUCHAEIDIUM. Calyx tube much prolonged and slender beyond the ovary. Petals 



wedge-shaped and 8-lobed at summit, tapering into a short claw. Stamens only 4, 

 on slender filaments. Stigmas 2 or 4. Pod oblong-linear. Seeds slightly wing- 

 margined. Flowers never yellow. 



7. CENOTHERA. Calyx tube generally much prolonged beyond the ovary. Petals 



usually obovate or obcordate, with hardly any claw. Stigmas 4, long and slender 

 (rarely discoid). Stamens 8. Flowers yellow or white, or rose-red. 



8. GODETIA. Calyx tube beyond the linear or spindle-shaped ovary, inversely conical 



or funnel-shaped. Flowers open by day, scentless. Petals broad and fan-shaped 

 or wedge-shaped, the truncate summit generally eroded, lilac-purple, rose-color, or 

 sometimes white. Stigma with 4 linear or short and broad lobes. Anthers erect 

 (stamens 8) on short (the alternate ones on very short) and broadish filaments, curv- 

 ing after opening. 



** -H- -H. Flowers irregular and unsymmetrical ; calyx tube not extended. 



9. LOPEZIA. Flowers small. Calyx with 4 linear purplish lobes. Petals with claws, 4, 



turned towards the upper side of the flower, the two uppermost narrower and 

 with a callous gland on the summit of the claw, and what seems to be a fifth small 

 one (but is a sterile stamen transformed into a petal) stands before the lower lobe 

 of the calyx. Fertile stamen only one with an oblong anther. Style slender ; 

 stigma entire. Pod globular. 



* Fruit a berry, ^-celled. 



10. FUCHSIA. Flowers showy ; the tube of the highly colored calyx extended much 



beyond the ovary, bell-shaped, funnel-shaped, or tubular, the 4 lobes spreading. 

 Petals 4. Stamens 8. Style long and thread-shaped; stigma club-shaped or 

 capitate. 



* Capsule indehiscent, \-4-celled, the cells generally \ -seeded. 

 +- Parts of the flower in twos. 



11. CIRC^EA. Delicate low herbs, with opposite thin leaves, and very small whitish 



flowers in racemes. Calyx with 2 reflexed lobes, its tube slightly prolonged beyond 

 the 1-2-celled ovary, which becomes a 1-2-seeded little bur-like fruit, covered with 

 weak hooked bristles. Petals 2, obcordate. Stamens 2. Style slender, tipped 

 with a capitate stigma. 



+- +- Parts of the flower in threes or fours. 



12. GAURA. Herbs with alternate sessile leaves, and small or smallish flowers in racemes 



or spikes. Calyx with slender tube much prolonged beyond the 4-celled ovary. 

 Petals 4 (rarely 8), on claws, mostly turned toward the upper side of the flower. 

 Stamens 8 (or 6), these and the long style turned down ; a little scale-like appen- 

 dage before the base of each filament. Fruit small, 4-angled or ribbed, 1-4-seeded, 

 dry and nut-like. 



18. TRAPA. Aquatic herbs with leaves of two forms ; those submerged opposite and 

 pinnatisect, the floating ones clustered, rhomboid and dentate. Petals and stamens 

 4. Ovary 2-celled, becoming a large, top-shaped, very hard, nut-like fruit with 2 or 

 4 horns- 



