EVENING PRIMROSE FAMILY 161 



Calyx-lobes reflexed; petals showy, clawed; capsule coriaceous. 



Fertile stamens 4, the alternate ones rudimentary; petals 3-lobed. 



8. Clarkia. 

 Fertile stamens 8; petals entire, rhombic. 9. Phaeostoma. 



Anthers attached near tlie middle and versatile. 

 Stigma divided into 4 linear lobes. 



Stamens equal in length; capsule terete or round-angled. 



Ovules and seeds horizontal, inserted in 2 or rarely more rows, 



prismatic-angled; petals yellow. 10. Oenothera. 



Ovules and seeds ascending, in one row, not angled; buds droop- 

 ing; petals white or pink. 11. Anogr.\. 

 Stamens unequal in length, the alternate longer: capsule crested or 

 winged; plant acaulescent or low-stemmed. 

 Capsules with more or less distinct double crests on the angles; 



seed furrowed along the raphe. 12. P.\cnYLOPHUs. 



Capsules winged or at least sharply angled on the angles. 

 Plants acaulescent, cesoitose. 1.3. L.wauxia. 



Plan is caulescent, with wiry diffuse stems. 



14. Gaurella. 

 Stigma discoid or capitate. 



Stigma discoid; hj-panthium-tube funnelform above. 



Hypanthium-tube longer than the ovarj ; stigma entire. 



l.''i. Galpinsla.. 

 Hypanthium-tube shorter than the ovary; stigma 4-toothed. 



16. Meriolex. 

 Stigma capitate. 



Plant acaulescent; capsules 4- winged: hypanthium-tube tubular- 



cylindric. 17. Taraxia. 



Plant caulescent: capsules not winged; hypanthium-tube ob- 

 conic or funnelform. 

 Capsule linear, sessile, narrowed above. 



15. Sphaerostigma. 

 Capsule more or less clavate, pediceUed and obtu.se. 



19. Chylismia. 

 Fruit indehiscent, nut-like. 



Hypanthium-tube filiform: filaments unappendaged ; ovary 1-celled. 



20. Stexosiphon. 

 Hypanthium-tube obconic; filaments w^th scales at the base; ovarv 4-celled. 



21. G.\URA 

 Flowers 2-merous; fruit indeMscent, obovoid and bri-stly with hooked hairs. 



22. CiRCAEA. 



1. CHAMAENERION (Gesn.) Boehmer-Liidwig. Fire-weed. 



Style pubescent at the base: leaves lanceolate or linear-lanceolate, with the lateral veins 

 confluent in marginal loops. 

 Petals 15-20 mm. long: stem-leaves usually obtuse at the base. 1. C. exaltatum. 



Petals 8-12 mm. (rarely 15 mm.) long; leaves all acute at the base. 



2. C. spicatum. 

 Style glabroiis: lateral veins of the leaves obsolete, not looped. 



Leaves lanceolate to ovate, entire or nearly^ so; pod about 3 mm. thick. 



3. C. latifolium. 

 Leaves narrowly Unear-lanceolate, denticulate; pod about 2 mm. thick. 



4. C. subdentatum. 



2. EPILOBIUM (Gesn.) L. Willow-herb, Cotton-weed. 

 Petals purple, pink or wliite. 



Perennials: stigma entire or merely notched. 



Leaves oblong, oval, ovate, or lanceolate, usually dentate or denticulate. 



Plants with rosettes or turions: leaves ovate or lanceolate, usually broadest 

 below the middle, and distinctly denticulate or dentate {except some- 

 times in nos. 8, 9, and 16) 

 Stem pubescent throughout; leaves also pubescent, at least when young. 

 Pubescence consisting of long silky hairs. 1. E. ursinum. 



Pubescence short and dense, crisp or glandular. 



Petals 7-8 mm. long. 2. E. Sandbcrgii. 



Petals 4-5 mm. long. 



Leaves ovate, permanentlv glandidar, dark green. 



3. E. Palmeri. 

 Leaves lanceolate, glabrous in age, pale green. 



13. E. siramineum. 

 Stem glabrous below; leaves glabrous or nearly so. 



Flowers 7-8 mm. long: petals purple or dark pink; leaves ovate-lance- 

 olate. 

 Leaves sessile or nearly so; innovations by turions. 

 Seeds without apiculations; coma sessile. 



Plant taU, 5-10 dm. high; leaves dark green, sharply dentate. 



4. E. glandnlosum. 

 Plant low, 2-4 dm. high; leaves light green, more indistinctly 



denticulate. 5. E. ovali folium. 



Seeds with a pale hyaline beak at the apex. 6. E. breristi/lum. 



Leaves short-petioled; innovations by rosettes. 7. E. occidenlale. 



