6o4 



ONAGRACEAE. 



Vol. II. 



I. Lavauxia triloba (Nutt.) Spach. Three-lobed Primrose. Fig. 3059. 



Oenothera triloba Nutt. Journ. Acad.. Phil. 2: 118. 

 1821. 



Lavauxia triloba Spach, Hist. Veg. 4: 367. 1835. 



Perennial, nearly glabrous throughout. Leaves 

 petioled, runcinate-pinnatifid, sometimes dil- 

 ate, oblong-lanceolate in outline, 3'-l2' long, 

 sometimes 2' wide, the apex acute or acutish ; 

 flowers white or pink, i'-2i' broad; calyx-lobes 

 lanceolate, spreading, the tube slender, some- 

 what dilated at the summit, many times longer 

 than the ovary, 2'-^' long; petals often 3-lobed; 

 capsule ovoid, 4-wing-angled, reticulate veined, 

 6"-i2" long; seeds finely and densely tubercu- 

 late. 



In dry, often rocky soil, Kentucky and Tennessee 

 to Kansas, Utah and California, south to Missis- 

 sippi, Texas and northern Mexico. May-July. 



Lavauxia Watsoni (Britton) Small, of Kansas 

 and Nebraska, is described as dii^ering from this 

 species in being annual with smaller flowers and more abundant fruit. {Oenothera triloba var, 

 parviflora S. Wats.) 



2. Lavauxia brachycarpa (A. Gray) Britton. Short-podded Primrose. 



Fig. 3060. 



Oenothera brachycarpa A. Gray, PK Wright, i : 70- 

 1852. 



Lavauxia brachycarpa Britton, Mem. Torr. Club 5 : 235. 

 1894. 



Low, perennial by a stout root, acaulescent or 

 nearly so, softly canescent. Leaves basal, leathery, 

 ovate to narrowly oblong, 3-9' long, acute or ob- 

 tuse, lyrate-pinnatifid or sometimes nearly entire ; 

 petioles sometimes as long as the blade; flowers yel- 

 low, basal ; calyx canescent, its tube 2'-4' long, gradu- 

 ally dilated upward, its segments linear-lanceolate, 

 about one-half as long as the tube, the tips free in 

 the bud; petals I'-iJ' long, undulate; capsules 

 elliptic, 8"-g" long, leathery or corky, the angles very 

 thin, the faces somewhat wrinkled. 



Montana to Kansas, Texas and New Mexico. 

 July. 



April- 



14. GAURELLA Small, Bull. Torr. Club 23 : 183. i 



Low perennial canescent or strigillose herbs with wiry diffusely branched stems. Leaves 

 small, narrow, nearly entire or distantly toothed, narrowed into very short petioles. Flowers 

 axillary, sessile. Calyx purplish, its tube cylindric, slightly dilated at the throat, its seg- 

 ments narrow, slightly longer than the tube, their tips united in the bud. Petals obovate, 

 white or pink, spotted or striped with red. Stamens 8, the alternate ones longer; filaments 

 filiform-subulate; anthers linear. Ovary 4-angIed, short; united styles stout, enlarged above; 

 stigmas filiform. Capsules ovoid-pyramidal, sessile, attenuate into a curved beak, sharply 

 4-angled, the faces swollen. Seeds obovoid, angled, delicately striate. [Diminutive of Gawra.] 



A monotypic genus of the west-central United States. 



