ONAGRACEAE. 1 69 



Petals with claws. 243. Clarkia, 171. 



Petals without claws. 244. Boisduvalia, 172. 



Anthers attached near the middle, 

 versatile. 

 Stamens unequal, the outer ones 

 longer. 

 Annuals; small flowered, cau- 

 lescent. 245. Gayophytum, 172. 

 Biennials; large flowered, a- 



caulescent or nearly so. 246. Pachylophus, 173. 



Stamens equal. 



Stigmas deeply 4-cleft, the 



lobes linear. 247. Oenothera, 173. 



Stigmas entire or nearly so. 

 Calyx-tube longer than the 



ovary; flowers large. 248. Taraxia, 174. 

 Calyx-tube shorter than 



the ovary; flowers small. 249. Sphaerostigma, 174. 



239. CIRCAEA. 



Delicate perennial herbs with opposite leaves on slender 

 petioles; flowers white, in terminal or axillary racemes; parts of 

 the flower in twos; calyx-tube prolonged, deciduous; lobes re- 

 flexed; fruit indehiscent, small, bur-like, 1-2-celled, with hooked 

 hairs; cells 1 -seeded. 



Circaea pacifica Asch. & Magn. Nearly glabrous but pilose with white 

 hairs on the upper part of the stem, 12-50 cm. high; stem usually simple, 

 from a small tuber; leaves ovate-orbicular, nearly entire or slightly denticulate, 

 3.5-6 cm. long, base truncate or rarely cordate, apex acute or sometimes obtuse; 

 petioles one third as long to as long as the blade; bracts of the inflorescence 

 foliaceous, or setaceous or none; flowers 2.5-3 mm. long, rarely pinkish in the 

 buds; fruit mostly white-hairy. In moist shady woods. 



240. GAURA. 



Annual, biennial or perennial herbs, somewhat woody at base; 

 leaves alternate, sessile; flowers white or rose-colored, in spikes or 

 racemes; calyx-tube much prolonged beyond the ovary, 4-lobed, 

 rarely 3-lobed; petals 4, with claws, unequal; stamens mostly 8, 

 turned down; fruit hard and nut-like, 3- or 4-ribbed or angled, 

 indehiscent or nearly so, usually 1-celled and 1-4-seeded. 



Gaura parviflora Dougl. Annual, erect, 1-2 m. high, whitish-pubescent 

 throughout, the stems villous; leaves numerous, ovate or lanceolate, acute, 

 entire or denticulate, rounded at base, nearly sessile, silky-pubescent, some- 

 what villous-ciliate, 6-10 cm. long; flowers small, pink, 3-4 mm. broad, in 

 erect spikes, 8-30 cm. long; bracts lanceolate, quickly deciduous; fruit sessile, 

 fusiform, glabrous, 6-8 mm. long. In sandy soil in the warmer valleys. 



241. ISNARDIA. 



Annual, or perennial succulent herbs with prostrate creeping or 

 floating stems; leaves opposite, fleshy, narrowed into petioles 



