846 EPILOBIACEAE 



** Lower cauline leaves with obtuse blades, manifestly wider than 



those of the upper leaves, the teeth rather blunt. 4. M. Drummondiana. 



b. Leaf-blades linear-filiform. 5. M. capittifolia. 



B. Free portion of the hypanthium brown-purple within : stigma brown-purple. 



Plant, at least the upper portions, pale-pubescent : petals over 15 mm. long. 6. M. melanoglottis. 

 Plant glabrous or nearly so : petals less than 15 mm. long. 7. M. Hillii. 



1. Meriolix serrulata (Nutt. ) Walp. Stems often copiously branched at the base, 

 the branches canescent, 1-5 dm. high : leaf-blades spatulate to linear-oblong, or linear, 2-5 

 cm. long, serrate : hypanthium 3-4 mm. broad at the mouth, the free portion yellow 

 within : sepals 5-7 mm. long : petals obovate, 8-12 mm. long, crenulate : anthers 2.5-3 mm. 

 long : capsules linear-cylindric, 1.5-2 cm. long, about 1.5 mm. thick. [Oenothera serrulata 

 Nutt.] 



In dry soil, Manitoba and Minnesota to Texas and New Mexico. 



2. Meriolix intermedia Rydb. Similar to M. serrulata in habit, but mostly taller, 

 and larger throughout. Stem and leaves, especially on the upper part of the plant, 

 markedly whitish or grayish pubescent : leaf-blades spatulate to linear, 4-7 cm. long, or 

 shorter on the branches, serrate : hypanthium 6-10 mm. broad at the mouth, the free por- 

 tion yellow within : sepals 7-8 mm. long : petals 2-2.5 cm. long : capsules 2-2.5 cm. long, 

 pubescent. 



In dry or stony soil, Manitoba to Minnesota and Texas. 



3. Meriolix splnulosa (T. & G. ) Heller. Similar to M. serrulata in habit, but more 

 slender : leaf-blades linear-spatulate to narrowly linear, 3-8 cm. long, or sometimes shorter, 

 spinulose-serrate, or sharply serrate : hypanthium 4-5 mm. broad at the mouth, the free 

 portion yellow within: sepals 5-6 mm. long: petals 18-22 mm. long: anthers 4-4. 5 mm. 

 long : capsules 2-3 cm. long, about 2 mm. thick, sparingly pubescent. [ Oenothera serrulata 

 T. & G.] 



On plains or prairies, Arkansas to Texas and New Mexico. 



4. Meriolix Drummondiana (Spach.) Small. Stem branched at the base, the 

 branches ascending or decumbent, 0.5-3 dm. long, sometimes branched above : leaf-blades 

 various, those of the lower cauline leaves spatulate, 1-2 cm. long, obtuse, rather bluntly 

 toothed, those of the upper cauline leaves linear, usually narrowly so, more sharply but 

 less prominently toothed than those of the lower leaves : hypanthium 5-6 mm. wide at the 

 mouth, the free portion yellow within : sepals 5-6 mm. long : petals 2-2.5 cm. long : an- 

 thers 4r-4. 5 mm. long: capsules 1-1.5 cm. long, sparingly pubescent. [Calylopkis Drum- 

 mondiana Spach. ] 



In open woods or dry soil, Texas. 



5. Meriolix capillifdlia (Scheele) Small. Stem branched at the base, the branches 

 3-5 dm. tall, slender, glabrous or nearly so : leaf-blades linear-filiform or very narrowly 

 linear, 2-5 cm. long, entire or essentially so, revolute : hypanthium 3-4 mm. broad at the 

 throat, yellow within : sepals 5-6 mm. long : petals 15-20 mm. long : anthers 3-4 mm. 

 long : capsules 2-2. 5 cm. long, 1-1.5 mm. thick. [Oenothera capillifolia Scheele. Oenothera 

 serrulata var. pinifolia Engelm.] 



In dry or stony soil, Texas. 



6. Meriolix melanoglottis Rydb. Stem usually branched at the base, the branches 

 ascending or decumbent, 2.5-4 dm. tall, the upper portion as well as the leaves, pale- 

 pubescent, the bark yellowish : leaf -blades spatulate to almost linear, 2.5-6 cm. long, 

 rather shallowly serrate, flat : hypanthium 5-6 mm. wide at the mouth, the free portion 

 brown-purple within : capsules straight, nearly 2 cm. long, copiously pubescent. 



In dry soil, Texas to Colorado. 



7. Meriolix Hillii Small. More slender than M. melanoglottis, glabrous or nearly 

 so, the branches often wiry, the bark whitish : leaf-blades narrowly linear-spatulate to 

 narrowly linear, 2-4.5 cm. long, sinuate-toothed, involute : hypanthium 3-4 mm. wide at 

 the mouth, the free portion brown-purple within : capsules more slender than those of M. 

 melanoglottis, incurved, nearly glabrous. 



In dry or sandy soil, Texas. 



17. GAURA L. 



Annual, biennial or perennial herbs, with branching stems. Leaves alternate : blades 

 narrow, or relatively so. Flowers in terminal spikes or racemes. Hypanthium narrow, 

 prolonged beyond the ovary. Sepals 4 or rarely 3. Petals unequal, with clawed blades. 

 Stamens usually 8, declined, each filament with a small scale at the base. Ovary 4-celled : 

 style declined : stigma 4-lobed, surrounded by a cup-like border. Ovules usually 4, pen- 



