EPILOBIACEAE 845 



ovary. Corolla yellow. Ovary 4-celled, elongated : stigma disk-like, entire. Capsule 

 elongated, narrowed at the base, more or less curved. Seeds sometimes tuberculate. 

 PRIMROSE. 



Free portion of the hypanthium 9-13 mm. long, the lower portion very slender. 1. <?. tubicula. 

 Free portion of the hypanthium 30-50 mm. long, the lower portion relatively stout. 



Low copiously tufted plants about 1dm. tall: leaves very numerous and crowded. 2. G. lavendulaefolia. 

 Relatively tall, not copiously tufted plants, mostly 2 or 3 dm. tall : leaves not 



conspicuously numerous. 

 Hypanthium about 10 mm. wide at the mouth. 



Stem and lower portion of the hypanthium glabrous or slightly canescent : 



leaf-blades mainly linear. 3. G. Hartivegii. 



Stem and lower portion of the hypanthium hirsute-tomentose : leaf- 

 blades mainly oblong. 4. G. interior. 

 Hypanthium about 15 mm. wide at the mouth. 5. G. Fendleri. 



1. Galpinsia tubicula (A. Gray) Small. Stems erect, 1-3 dm. tall, somewhat 

 branched, flexuous, its bark thin and papery : leaves numerous but not crowded ; blades 

 linear or lanceolate, 1-2 cm. long, acute, entire, nearly glabrous or slightly glandular- 

 pubescent, short-petioled or nearly sessile : flowers usually near the ends of the branches': 

 hypanthium abruptly and widely dilated above : sepals lanceolate, 6-8 mm. long : petals 

 9-12 mm. long, obtuse or apiculate : capsules cylindric, 1.2-1.8 cm. long, constricted be- 

 low the summit, somewhat angled. [ Oenothera tubicula A. Gray. ] 



On plains, Texas and New Mexico. Spring and summer. 



2 Galpinsia lavendulaefolia (T. & G.). Small. Stems copiously tufted, radially 

 spreading and seldom rising more than 1 dm., the internodes very short : leaves very 

 numerous and crowded ; blades linear or linear-spatulate on the lower part of the stem, 

 entire or essentially so, finely but closely pale-pubescent : flowers few : hypanthium elon- 

 gated, rather gradually dilated : sepals 11-16 mm. long : petals 13-19 mm. long : capsules 

 narrow, 2-2.5 cm. long. [Oenothera lavendulaefolia T. & G. ] 



On plains or prairies, Kansas to Wyoming, Texas, Arizona and New Mexico. Spring to fall. 



3. Galpinsia Hartwegii (Benth. ) Britton. Stems more or less branched, but not 

 densely tufted, mostly 2-4 dm. tall : leaves sometimes many but not crowded ; blades linear, 

 1-3.5 cm. long, entire or slightly repand-denticulate : flowers few : hypanthium elongated, 

 rather gradually dilated : sepals about 2 cm. long : petals 2-3 cm. long : capsule narrowly 

 cylindric, 12-25 mm. long. [Oenothera Hartwegii Benth. 1 



On prairies, Nebraska and Colorado to Texas and northern Mexico. Spring to fall. 



4. Galpinsia interior Small. Stems somewhat tufted, erect or ascending, 2-3 dm. 

 tall, hirsute-tomentose : leaves often rather numerous but not densely crowded ; blades 

 mainly oblong, 1-2.5 cm. long, entire, sessile and partly clasping : flowers few : hypanthium 

 elongated, rather gradually dilated, about 10 mm. wide at the mouth, hirsute-tomentose 

 near the base : sepals 1-1.5 cm. long : petals 1.5-2.5 cm. long : capsules 1.5-2 cm. long. 



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



5. Galpinsia Fendleri (A. Gray) Heller. Stems loosely tufted, more or less spread- 

 ing, 2-4 dm. tall, rather stout, slightly glandular-pubescent : leaves relatively few ; blades 

 mainly oblong, varying to oblong-lanceolate, 2-3 cm. long, abruptly narrowed at the base, 

 sessile : flowers few : hypanthium elongated, gradually dilated, about 15 mm. wide at the 

 mouth : sepals 2-2.5 cm. long : petals 2.5-3.5 cm. long : capsules narrow, 2-2.5 cm. long. 

 [ Oenothera Fendleri A. Gray. ] 



In dry or stony soil, Texas and New Mexico. Spring and summer. 



16. MERIOLIX Raf. 



Biennial or perennial herbs, with branched stems, or sometimes shrubby plants. 

 Leaves alternate : blades narrow, entire or sharply serrate. Flowers regular, axillary, 

 yellow. Hypanthium funnelform, the free portion mostly shorter than the ovary, abruptly 

 and widely dilated above. Sepals keeled on the back. Petals mostly yellow, often blotched 

 at the base. Stigma disk-like, 4-toothed. Capsule linear, 4-angled, sessile. Seeds 

 longitudinally grooved. The plants flower mainly in the spring and summer. PRIMROSE. 



A. Free portion of the hypanthium yellow within : stigma yellow. 



Petals less than 15 mm. long. 1. M. serrulata. 



Petals over 15 mm. long. 



a. Leaf-blades spatulate to oblanceolate or linear. 



Stem and leaves markedly whitish or grayish pubescent. 2. M. intermedia. 



Stem and leaves glabrous or nearly so. 



* Lower cauline leaves with acute blades, scarcely wider than those 

 of the upper leaves, the teeth sharp or spinulose. 



3. M. spinulosa. 



