604 ONAGRACEAE 



the same size, ovate, 2-3 cm. long, glabrous, veiny, sharply serrate; free tube of 

 hypanthium 3 mm. long; petals yellow, about 1 cm. long; pod linear, spreading. 

 O. multijuga S. Wats. Dry places: s Utah. Mr. 



20. STENOSIPHON Spach. 



Perennial herbs, with erect leafy stem. Leaves alternate, sessile, narrow. 

 Flowers perfect, in elongate terminal spikes. Hypanthium much produced 

 beyond the ovary into a filiform tube. Sepals 4, reflexed. Petals white, clawed. 

 Stamens 8, declined, without scales at the base. Ovary 1-celled; stigma 4-lobed, 

 surrounded by a cup-like border. Fruit 8-ribbed, indehiscent, 1-celled, 1-seeded. 



1. S. linifolium (Nutt.) Britton. Stem slender, glabrous, 6^15 dm. high; 

 leaves lanceolate to linear, 2.5-5 cm. long, entire, acuminate; spikes elongate, 

 sometimes 3 dm. long; tube of the hypanthium about 1 cm. long; petals white, 

 long-clawed, about 5 mm. long; fruit ovoid, hirsutulous, rugose, 3-4 mm. long. 

 Dry plains and prairies: Neb. Ark. Tex. Colo.; Mex. Jl-S. 



21. GAURA L. BUTTERFLY WEED. 



Annual, biennial, or perennial caulescent herbs, with branching stems. 

 Leaves alternate, usually narrow. Flowers perfect, in terminal racemes or pan- 

 icles, or spikes. Hypanthium prolonged beyond the ovary into a slender but 

 short tube. Sepals 4, rarely 3. Petals clawed, unequal. Stamens usually 8, 

 declined, with a small scale at the base of the filament. Ovary 4-celled; style 

 declined; stigma 4-lobed, with a cup-like border below. Fruit nut-like, inde- 

 hiscent, ribbed or angled, 4-celled, but some of the cells usually empty. Seeds 

 1-4. 



Anthers oval, attached near the middle; fruit fusiform, sessile, almost equally 8-ribbed. 



1. G. parviflora. 

 Anthers linear or nearly so, attached near the base; fruit strongly 4-angled, at least 



above. 



Fruit sessile, broadly fusiform; tall biennials. 2. G. neomexicana. 



Fruit prolonged below into a stipe-like base. 



Stipe-like base slender; fruit fusiform; tall herbaceous plant. 3. G. coloradensis. 

 Stipe-like base thick; body of the fruit pyramidal-ovoid; low plants, with sublig- 



neous base. 

 Plants more or less pubescent. 



Leaves canescent, the lower usually oblong and sinuately toothed. 



4. G. coccinea. 

 Leaves sparingly strigose, all linear or nearly so and entire. 



5. G. parvifolia. 

 Plant glabrous or nearly so, except the strigose hypanthium. 



6. G. glabra. 



1. G. parviflora Dougl. Biennial; stem 6-15 dm. high, silky-pilose, with 

 long spreading hairs; leaves lanceolate, ovate-lanceolate, or elliptic, 3.5-10 cm. 

 long, acute or acuminate, repand-dentate, softly pilose; spike very long; petals 

 2.5-4 mm. long; fruit 6-8 mm. long, glabrous or nearly so. Plains, valleys, and 

 prairies: S.D. Mo. La. Ariz. Wash.; Mex. Plain Submont. My-O. 



2. G. neomexicana Wooton. Perennial; stems usually more than one from 

 the woody root, 4-7 dm. high, villous, somewhat glandular in the inflorescence; 

 leaves lanceolate, 5-10 cm. long, entire or sinuately toothed; flowers sessile; tube 

 of hypanthium 1 cm. long; petals 1 cm. long, rose-pink; fruit obo void -pyramidal, 

 7-8 mm. long, 3-4 mm. broad, sessile. Valleys: N.M. Colo. Submont. Je. 



3. G. coloradensis Rydb. Herbaceous biennial or perennial, with fusi- 

 form root; stem 5-7 dm. high, strict, but somewhat branched, finely strigose, 

 more or less red; leaf -blades narrowly oblanceolate, 5-10 cm. long, gradually 

 tapering below into a short petiole, or the upper sessile, callous-denticulate, 

 finely strigose; hypanthium about 2 cm. long, finely strigose; petals about 8 mm. 

 long, spatulate, pink; fruit 8-10 mm. long. Meadows: Colo. Submont. Jl. 



4. G. coccinea Nutt. Stems several, branched, strigose or puberulent and 

 more or less hirsute, 1-5 dm. high; leaves numerous, sessile, oblong or lanceolate, 

 the upper linear-lanceolate, repand-dentate or entire, .1-3.5 cm. long, canes- 

 cent; tube of hypanthium 6-8 mm. long; petals from pink or white to scarlet, 



