ONAGRACEAE (EVENING-PRIMROSE FAMILY) 157 



A. Leaves opposite, not all basal. 



B. Calyx segments 2, petals 2, stamens 2; capsule obovate, leaves ovate to cor- 

 date. CIRCAEA (p. 161) 

 BB. Calyx segments 4, petals 4, stamens 4 or 8; capsule mostly not obovate; 

 leaves in most species narrow. 



C. Stems procumbent or floating; leaves entire; stamens 4; capsules about 

 3 mm. long; calyx segments persistent on the capsule; seeds not hairy. W. E. 

 (Honor of C. G. Ludwig, a German botanist.) 



Ludwigia palustris (WATER PURSLANE) 



CC. Stems neither procumbent nor floating, erect to decument or caespitose; 

 leaves often not entire; stamens 8; capsule 10 mm. or more long; calyx seg- 

 ments deciduous from the capsule; seed long-hairy at one end. 



EPILOBIUM (p. 158) 

 AA. Leaves alternate or all basal. 

 D. Plants with evident stems. 



E. Lower leaves often opposite; stamens 8; seed with a tuft of long hairs at one 

 end. EPILOBIUM (p. 158) 



EE. Leaves all alternate; stamens 4 or 8; seed without a tuft of hairs at one end. 

 F. Anthers versatile. 



G. Stigma plainly 4-lobed or -cleft; leaves not entire. 



H. Flowers axillary, white, becoming rose-colored in age; some species with 



pinnatifid leaves; capsule not nutlike, elongated, many-seeded; seeds in 



i row in each cell of the pod. ANOGRA (p. 160) 



HH. Flowers in terminal spikes, yellow or rose-colored; no species with 



pinnatifid leaves. 



I. Petals yellow, sometimes becoming pink in age, obcordate; capsule 

 elongated, not nutlike, many -seeded; seeds in two rows in each cell. 



ONAGRA (p. 159) 



II. Petals rose-colored, spatulate; capsule oblong, nutlike, i-4-seeded. 

 E. (Gk. gauros = superb; some species have fine flowers.) 



Gaura parviflora (SMALL-FLOWERED GAURA) 



GG. Stigma either 2-lobed or else capitate and not lobed; leaves entire or not. 

 J. Leaves lyrafely pinnate or pinnatifid. CHYLISMA (p. 161) 



JJ. Leaves entire or denticulate. 



K. Leaves denticulate or entire, linear or wider; calyx tube prolonged be- 

 yond the ovary; ovary 4-celled. SPHAEROSTIGMA (p. 160) 

 KK. Leaves entire, linear; calyx tube not prolonged beyond the ovary; 

 ovary 2-celled. GAYOPHYTUM (p. 161) 

 FF. Anthers not versatile. 



L. Fruit dehiscent by valves, elongated, not nutlike, many-seeded; leaves 

 entire to dentate. 



M. Calyx lobes erect; petals 2-lobed, sessile. BOISPUVALIA (p. 158) 



MM. Calyx lobes reflexed; petals 3-lobed or entire. 



N. Petals sessile, entire, rose or violet; leaves entire. GODETIA (p. 159) 



NN. Petals clawed, 3-lobed or entire, purple or violet; leaves entire to 



dentate. CLARKIA (p. 158) 



LL. Fruit indehiscent, nutlike, i-2-seeded; stigma disklike, entire; petals 



clawed; leaves entire. U. (Gk. heteros = unlike; + Gaura = another 



genus.) Heterogaura californica 



