ONAGRACEAE (EVENING PRIMROSE FAMILY^) 601 



§ 5 LAVAtJXIA (Spach) Endl. Stigma-lohes linear; flowers white or rose- 

 colored; fruit ovoid, i-winyed ; acaulescent. 



18. 0. triloba Nutt. Biennial or perennial, nearly glabrous ; leaves 1-3 dm. 

 long, somewhat ciliate, long-petioled, runcinate-pinnatifid or oblanceolate and 

 only sinuate-toothed ; calyx-tips free, the tube slender, 6-20 cm. long ; petals 

 1.2-4 cm. long; capsule ovoid to ellipsoid, 2-3.5 cm. long, strongly winged, 

 net-veined. (Lavauxia Spach.) — Shaly limestone crevices, etc., Ky. and Tenn. ; 

 Assina. to Kan., Tex., and westw. (Mex.) 



Var. (?) parviflbra Wats. Seemingly annual; flowers very small, 2.5-5 cm. 

 long, fertilized in the bud and rarely opening fully ; fruit abundant, forming 

 at length a densely crowded hemispherical or cylindrical mass nearly 5 cm. 

 in diameter and often 6-7 cm. high. (Lavauxia triloba, var. Watsoni 

 Britton.) — Plains, Kan. and Neb. — Little known. 



§6. MEGAPTERIUM (Spach) Endl. Stigma-lohes linear ; flowers yellow; 

 fruit ellipsoidal to suborbicular, broadly 4:-winged; seeds in a double row 

 in each cell, crested ; caulescent. 



19. 0. missouriensis Sims. Decumbent, canescent-puberulent or glabrate ; 

 leaves thick, lanceolate to lance-elliptic, 5-12 cm. long, acute or acuminate, 

 entire or repand-denticulate ; calyx-tube 5-14 cm. long ; petals broad, 3-6 cm. 

 long; capsule 5-8 cm. long. {Megapterium Spach.) — Limestone cliffs and 

 barrens. Mo. to Neb., Col., and soutli westw. 



§ 7. CALYLOPHIS [Spach] T. & G. Stigma dishMke, scarcely lobed ; calyx- 

 tube funnel-form with broadly dilated throat; flowers yellow; capsule 

 linear-cylindric, elongated ; suffrutescent. 



20. 0. serrulita Nutt. Slender, 1-6 dm. high, simple or branched, canescent 

 on the younger parts ; leaves linear to linear-lanceolate, 2-6 cm. long, sub- 

 entire or shallowly denticulate ; calyx-tube 6-13 nun. long, the flaring throat 

 strongly nerved; petals broadly obovate, 8-17 mm. long, crenulate ; capsule 

 1.8-3 cm. long. {Meriolix Walp. ; M. intermedia Rydb. ?) — Sandy and rocky 

 places, Man. and w. Wise, to Mo., and south westw. 



5. GAURA L. 



Calyx-tube much prolonged beyond the ovary, deciduous ; the lobes 4 (rarely 

 3), ref^exed. Petals clawed, unequal or turned to the upper side. Stamens 

 mostly 8, often turned down, as is also the long style. A small scale-like 

 appendage before the base of each filament. Stigma 4-lobed, surrounded by a 

 ring or cup-like border. Fruit hard and nut-like, 3-4-ribbed or -angled, inde- 

 hiscent or nearly so, usually becoming 1-celled and 1-4-seeded. Seeds naked. — 

 Leaves alternate, sessile. Flowers rose-color or white, changing to reddish in 

 fading, in spikes or racemes, in our species quite small (so that the name, 

 from yavpos, superb, does not seem appropriate). 



* Fruit sessile or nearly so. 



1. G. biennis L. Soft-hairy or downy, 1-3.2 m. high ; leaves oblong -lanceo- 

 late, denticulate ; spikes wand-like ; fruit ovoid-fusiform, 4-angled, acute at 

 both ends, 4-6 mm. long, ribbed, downy. —Dry banks, w. Que. to Ct. (Bishop), 

 Minn., Neb., and south w. ; casual in e. N. E. 



2. G. parviflbra Dougl. Soft-villous and puberulent, 1-3.6 m. high ; leaves 

 ovate-lanceolate, repand-denticulate, soft-pubescent ; spikes dense; fruit fusi- 

 form or clavate, narrowed to both ends, 4-nerved, obtusely angled above, OS 

 mm. long. — la. and Neb. to Mo., La., and westw. 



3. G. coccinea Pursh. Canescent, puberulent or glabrate, 1.6-4 dm. high, 

 very leafy ; leaves lanceolate, linear-oblong or linear, repand-dentirulate or 

 entire ; flowers in simple spikes, rose-color turning to scarlet ; fruit terete below, 

 4-sided and broader above, 4-6 mm. long. — Man. to Mo. (Bush), N. Mex., and 

 westw. ; introduced about Rochester, N. Y. (M. S. Baxter, V. Dewing) 



