VOL. II.] 



EVENING-PRIMROSE FAMILY. 



493 



13. LAVAUXIA Spach, Hist. Veg. 4: 366. 1835. 



Low perennial usually acaulescent herbs, rarely producing short stems. Leaves mostly 

 basal, pinnatifid, numerous. Flowers perfect, white, pink or pale yellow. Calyx-tube 

 slender, dilated at the throat; calyx-segments finally reflexed, the tips free in the bud or 

 united. Petals 4, spreading. Stamens 8, the alternate ones longer; filaments filiform; an- 

 thers linear. Ovary short, 4-angled; stigma 4-cleft; ovules few. Capsules stout, their angles 

 sometimes winged above. Seeds few. [In honor of Francois Delavaux, founder of the botan- 

 ical garden at Nismes.] 



About 6 species, chiefly in southern North America. 



Leaves membranous; capsules beaked, glabrate. i. L. triloba. 



Leaves leathery; capsules hardly beaked, pubescent. 2. L. brachycarpa. 



i. Lavauxia triloba (Nutt.) Spaeh. 

 Three-lobed Primrose. (Fig. 2596.) 



OEnothera triloba Nutt. Journ. Acad. Phil. 2: 



1 18. 1821. 

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



Nearly glabrous throughout. Leaves pet- 

 ioled, runcinate-pinnatifid, or sinuate, some- 

 times ciliate, oblong-lanceolate in outline, 3'- 

 i2 / long, sometimes 2' wide, the apex acute 

 or acutish; flowers white or pink, i'-2%' 

 broad; calyx lobes lanceolate, spreading, the 

 tube slender, somewhat dilated at the summit, 

 many times longer than the ovary, 2 / ~4 / long; 

 petals often 3-lobed; capsule ovoid, 4 : wing- 

 angled, reticulate veined, 6 // -i2 // long; seeds 

 finely and densely tuberculate. 



In dry soil, Kentucky and Tennessee to Arkan- 

 sas, Utah and California, south to Mississippi, 

 Texas and northern Mexico. May-July. 



Lavauxia triloba Watsonii Britton, Mem. Torr. Club, 5: 235. 1894. 

 OEnolhera triloba var. parvifiora S. Wats. Proc. Am. Acad. 12: 251. 1876. 



Annual; flowers smaller; fruit densely crowded. Perhaps a distinct species. Kansas (and 

 Nebraska?). 



2. Lavauxia brachycarpa (A. Gray) Brit- 

 ton. Short-podded Primrose. 

 (Fig. 2597.) 



OEnothera brachycarpa A. Gray. PI. 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, $'-<)' 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'-^' long, grad- 

 ually dilated upward, its segments linear-lanceo- 

 late, about one-half as long as the tube, the tips 

 free in the bud; petals i'-i%' long, undulate; cap- 

 sules elliptic, 8"-9" long, leathery or corky, the 

 angles very thin, the faces somewhat wrinkled. 



Montana to Kansas, Texas and New Mexico. April- 

 July. 



14. GAURELLA Small, Bull. Torr. Club, 23: 183. 1896. 

 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-angled, short; united styles stout, enlarged 



