ONAGRACEAE. 66 1 



tube 5-18 mm. long, dilated at the mouth; capsule sessile, ovoid, strongly tuber- 

 culate on each side, the angles ribbed; seeds minutely tuberculate. Neb. and 

 Mont, to the N. W. Terr., Nev., N. Mex. and Sonora. June-July. 



13. LAVAUXIA Spach. 



Low usually perennial acaulescent herbs. Leaves mostly basal, pinnatifid. 

 Flowers white, pink or pale yellow. Calyx-tube slender. Ovary short, 4-angled; 

 ovules few. Capsules stout, their angles sometimes winged above. Seeds few. [In 

 honor of Francois Delavaux, founder of the botanical garden at Nismes.] About 6 

 species, chiefly in southern N. Am. 



Leaves membranous ; capsules beaked, glabrate. 1. L. triloba. 



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



i. Lavauxia triloba (Nutt.) Spach. Three-lobed Primrose. (I. F. f. 

 2596.) Nearly glabrous throughout. Leaves runcinate-pinnatifid, or sinuate, 

 sometimes ciliate, oblong-lanceolate in outline, 7-30 cm. long; flowers white or 

 pink, 2.5-6 cm. broad; petals often 3-lobed; capsule ovoid, 4-wing-angled, retic- 

 ulate-veined, 12-25 mm. long; seeds finely and densely tuberculate. In dry soil, 

 Ky. and Tenn. to Kans., Cal., Miss., Tex. and northern Mex. May-July. 



Lavauxia triloba Watsonii Britton. Annual; flowers smaller; fruit densely crowded. 

 Perhaps a distinct species. Kans. 



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

 (I. F. f. 2597.) Softly canescent. Leaves basal, ovate to narrowly oblong, 7.5- 

 22 cm. long, lyrate-pinnatifid or sometimes nearly entire; petioles sometimes as 

 long as the blade; flowers yellow, basal; petals undulate; capsules elliptic, 16-18 

 mm. long, leathery or corky, the angles very thin, the faces somewhat wrinkled. 

 Mont, to Kans., Tex. and N. Mex. April-July. 



14. GAURELLA Small. 



Low perennial herbs with wiry diffusely branched stems. Leaves nearly entire 

 or distantly toothed. Flowers axillary, sessile. Calyx-tube slightly dilated at the 

 throat, its segments slightly longer than the tube. Petals white or pink, spotted or 

 striped with red. Ovary short; united styles stout, enlarged above. Capsules ses- 

 sile, with a curved beak, the faces swollen. Seeds angled, delicately striate 

 [Diminutive of Gaura.] A monotypic genus of the west-central U. S. 



1. Gaurella guttulata (Geyer) Small. Spotted Primrose. (I. F. f. 2598.) 

 Stems 1-2 dm. high, canescent with appressed hairs, the branches decumbent or 

 ascending. Leaves lanceolate or linear-lanceolate, obtusish at the apex, 8-16 mm. 

 long, repand-denticulate or entire; flowers white or pink, 18-25 mm - wide; petals 

 obovate, entire; capsule canescent, 8-10 mm. long, angled, not winged; seeds 

 angled, slipper-shaped. Prairies, Neb. to N. Mex. June-Sept. 



15. MEGAPTERIUM Spach. 

 Spreading perennial herbs with stout stems. Leaves alternate, entire or slightly 

 toothed. Flowers few, but large and showy, axillary, yellow. Calyx-tube much 

 elongated. Ovary 4-angled or 4-winged; united styles filiform; ovules few, sessile. 

 Capsules broadly 4-winged. Seeds crested. [Greek, broad- winged. J About 3 

 species, in N. Am. and Mex. 



Corollas 7.5-15 cm. broad; capsules 5-7.5 cm. long, with suborbicular wings. 



_i „ . . -, 1. M. Missouriense. 



Corollas 2.5-5 cm - broad; capsules 1.8-3 cm - Ion?, with oblong wings. 



Pubescent; capsules mostly less than 2.5 cm. long. 2. M. Fremont ii 



Glabrous; capsules mostly over 2.5 cm. long. 3' m\ Oklahomense. 



i. Megapterium Missouriense (Sims) Spach. Missouri Primrose. (I. F. 

 f. 2599.) _ Stems decumbent or ascending, densely canescent 1.5-6 dm. long. 

 Leaves thick, linear-lanceolate or oblong-lanceolate, acuminate or acute at the apex, 

 entire or remotely denticulate, 5- 15 cm. long; flowers 7.5-15 cm. broad; calyx- 

 tube 5-15 cm. long; capsule short-stalked, nearly orbicular, very broadly winged. 

 In dry soil, Mo. and Neb. to Tex. May-July. 



