60 ONAGBACEiE. (EVENING PEIMROSE FAMILT.) 



4. CENOTHERA, L. 



Calyx tube more or less prolonged beyond the ovary; segments reflexed. Petals 4; in 

 our species yellow. Stamens 8, equal, or those opposite to the petals shorter. Style 

 filiform; stigma 4-lobed or capitate. (See Addenda. ) 



* Acaulescent. Calyx-tube fXiforra above iht under-ground ovary. 



Leaves ovate to lanceolate CE. ovata. 1 



Leaves linear CB. graciliflora. 2 



* * Caulescent. Calyx-tube obconic; capsule sessile^ linear. 



Leaves thick; flowers small; capsule thick CE. cheiranthifolia. 3 



Flowers large; petals with a spot at the base CE. bistorta. 4 



Flowers small; capsule contorted CE. micrantha. 5 



Slender, leajy annuals; leaves linear; Jlowers small; capsule narrowly linear. 



Flowers rarely reddening CE. dentata. 6 



Flowers usually reddening CE. strigulosa. 7 



1. CB. ovata, Nutt. The radical leaves 4 to 6 inches long; calyx-tube scape-like, 

 1 to 4 inches long. 



2. CE. graciliflora, Hook & Am. Canescently villous; calyx-tube equaling the 

 leaves, 6 to 18 lines long; petals obcordate, 3 to 5 lines long, smaller than the last. 



3. OEj. cheiranthifolia, Horn. Canescently pubescent; stems decumbent or ascend- 

 ing, 2 ft. long or more; leaves oblong or narrowly oblanceolate, sometimes broadly ovate 

 or cordate, ^ to 2^ inches long, mostly entire, the lower petioled, the upper often clasp- 

 ing; ovary and calyx villous; flowers 2 to 5 lines in diameter; capsule 4 to 8 lines long. 

 Near the sea on drifting sands. 



4. CE. bistorta, Nutt. Less common than the last; distinguished by its petals, 4 

 to 6 lines long, usually with a brown spot. 



5. CE. micrantha, Horn. A variable species distinguished from the last by its 

 flowers, only 2 to 4 lines in diameter, with the petals sometimes 3-lobed; and by the con- 

 torted slender capsules, 8 to 18 lines long. 



6. CE. dentata, Cav. A span high or less; leaves linear, sessile, denticulate, 6 to 

 18 lines long; petals rounded, 2 to 4 lines long; capsule slender, attenuate, an inch long 

 or more. 



7. CE. strignlosa, Torr. & Gr. Like the last; the capsule obtuse, scarcely attenu- 

 ate. !More common than the last. 



CEnothera, biennis, L., the Evening Primrose, if found, may be known by its taU, 

 erect stem and large flowers. 



