844 EPILOBIACEAE 



4-angled. Ovules few. Capsule stout, the angles sometimes winged above. Seeds few. 



Pkimrose. 



Perennial : corolla 4-6.5 cm. broad, widely expanding : capsule 20-30 mm. long. 1. L. triloba. 



Annual : corolla 1-2 cm. broad, barely, if at all, expanding : capsule 10-15 mm. long. 2. L. Wolsonii. 



1. Lavauxia triloba (Nutt. ) Spach. Perennial, nearly glabrous throughout. Leaves 



basal ; blades oblong-lanceolate in outline, 7-30 cm. long, runcinate-pinnatifid or sinuate, 



sometimes ciliate : corolla white or pink, 4-6.5 cm. broad : petals often 3-lobed : capsules 



ovoid, 20-30 mm. long, manifestly longer than broad, 4-winged above, reticulate-veined. 



\_Oenothera triloba Nutt.] 



in dry soil, Kentucky and Tennessee to Wyoming, California, Mississippi, Texas and northern 

 Mexico. Spring and summer. 



2. Lavauxia Watsonii (Britton) >Small. Similar to L. triloba in habit, but smaller 

 and annual. Leaf-blades thinner and less finely pinnatifid : flowers fertilized mainly in 

 the bud, the corolla barely, if at all, expanding, 1-2 cm. broad : capsules 10-15 mm. long, 

 as broad as long at maturity, strongly ridged, few, or sometimes in a dense globular mass. 

 [_Larauxia triloba Watsonii Britton.] 



On prairies, Kansas to Oklahoma. Spring and summer. 



13. GAURELLA Small. 



Low perennial herbs, with wiry diffusely branched stems. Leaves alternate : blades 

 nearly entire or distantly toothed. Flowers axillary, sessile. Hypanthium slightly 

 dilated at the throat. Sepals slightly longer than the hypanthium. Petals white or pink, 

 spotted or striped with red. Ovary short : style stout, enlarged above. Capsule sessile, 

 with a curved beak, the faces swollen. Seeds angled, delicately striate. 



1. Gaurella guttul^ta (Geyer) Small. Stems 1-5 dm. long, canescent with appressed 

 hairs, the branches decumbent or ascending : leaf-blades lanceolate or linear-lanceolate, 

 8-16 mm. long, repand-denticulate or entire : corolla white or pink, 18-25 mm. wide : 

 petals obovate, entire : capsules canescent, 8-10 mm. long, angled, not winged : seeds 

 angled, slipper-shaped. [ Oenothera guttulata Geyer. ] 



On prairies, Nebraska to New Mexico. Summer and fall. 



14. MEGAPTERIUM Spach. 

 Perennial herbs, with stout spreading stems. Leaves alternate : blades entire or 

 slightly toothed, or rarely partly pinnatifid. Flowers few, but large and showy, axillary 

 to leaf-like bracts. Sepals elongated. Corolla yellow. Ovary 4-angled or 4-winged : style 

 filiform. Ovules few, sessile. Capsules broadly 4-winged. Seeds crested. Primrose. 



Petals 2-A cm. long: capsules less than 5 cm. long, oblong to oval. 



Stem and leaves closely pubescent : capsules less than 2 cm. wide. 1. M. Premontii. 



Stem and leaves glabrous : capsules over 2 cm. wide. 2. M. Oklafiomense. 



Petals 5-7 mm. long : capsules over 5 mm. long, suborbicular. 3. M. Missouriente. 



1. Megapterium Premdntii (S. Wats.) Britton. Stems ascending, 5-15 cm. long, 

 closely appressed-pubescent : leaf-blades lanceolate to somewhat oblanceolate, or linear, 

 3.5-7.5 cm. long, acuminate at the apex, entire or very nearly so, silvery canescent : sepals 

 2.5-3.5 cm. long : petals 3-4 cm. long: capsules oblong, 2-2.5 cm. long, winged, rounded 

 at the summit. [ Oenothera Fremontii S. Wats. ] 



On plains and prairies. Kansas to Texas. Summer. 



2. Megapterium Oklahoni6nse Norton. Stems or branches 1.5-3 dm. long, glabrous : 

 leaves rather numerous; blades lanceolate or almost oblong, 4-9 cm. long, remotely toothed 

 or merely undulate, glabrous : sepals nearly 2 cm. long : petals 1.5-2.5 cm. broad : capsules 

 oblong or oval, 2.5-3.5 cm. long, rounded at the summit. 



On prairies and hillsides, Kansas to Oklahoma and Texas. Summer. 



3. Megapterium Missouri^nse (Sims) Spach. Stems decumbent or ascending, 

 densely canescent, 1.5-6 cm. long : leaf-blades thick, linear-lanceolate or oblong-lanceolate, 

 5-15 cm. long, acuminate or acute at the apex, entire or remotely denticulate : sepals 

 4.5-5.5 cm. long: petals 5-7 cm. long: capsules nearly orbicular, fully 5 cm. long, very 

 broadly winged. \_Oenothera Missounense Sims.] 



On plains or prairies, Missouri and Nebraska to Texas. Spring and summer. 



15. GALPINSIA Britton. 

 Perennial herbs or shrubby plants, with branched stems. Leaves alternate. Flowers 

 axillary to leaf-like bracts. Hypanthium slender, the upper portion longer than the 



