6o8 



ONAGRACEAE. 



Vol. II. 



I. Meriolix serrulata (Nutt.) Walp. Tooth-leaved Primrose. Fig. 3067. 



Oenothera serrulata Nutt. Gen. i : 246. 1818. 



Meriolix serrulata Walp. Repert. 2 ; 79. 1843. 



M. intermedia Rydb. ; Small, Fl. SE. U. S. 846. 1903, 



Erect, simple or branched, canescent or glabrate, 

 4'-i8' high'. Leave& linear-oblong, lanceolate or 

 oblanceolate, acute or acutish at the apex, narrowed 

 at the base and usually sessile, sharply dentate or 

 denticulate, I'-z' long, 2"-3" wide; flowers yellow, 

 axillary, 6"-2' broad ; calyx-lobes ovate, acuminate, 

 somewhat reflexed, the tube funnelform, silvery 

 canescent, shorter than or equalling the ovary ; petals 

 obovate, crenulate ; stigma discoid; capsule sessile, 

 linear-cylindric, silvery canescent, 8"-i5" long, about 

 i" thick, slightly grooved longitudinally. 



In dry soil, Manitoba and Minnesota to Wisconsin, 

 Texas and New Mexico. Consists of several races, dif- 

 fering in size, shape of leaves and size of flowers. May- 

 July. 



G. biennis. 

 G, sinuaia. 



G. villosa. 



18. GAURA L. Sp. PI. 347- i753- 



Annual biennial or perennial herbs, somewhat woody at the base, with alternate nar- 

 row sessile leaves, and white, pink or red flowers in terminal spikes or racemes. Calyx 

 usually pubescent, its tube narrow, prolonged beyond the ovary, deciduous, 4-lobed (rarely 

 3-lobed), the lobes reflexed. Petals 4 (rarely 3), clawed, unequal. Stamens usually 8, 

 declined; filaments filiform, each with a small scale at the base. Ovary i-celled; united 

 styles filiform, declined; stigma 4-lobed, surrounded by a cup-like border; ovules usually 4, 

 pendulous. Fruit nut-like, ribbed or angled, indehiscent or nearly so, 1-4-seeded. Seeds 

 unappendaged. [Greek, proud, some species being showy.] 



About 18 species, natives of North America and Mexico. Type species: Gaura biennis L. 



Fruit sessile or very nearly so ; flowers spicate. 



Flowers i}4"-2" broad; stigma little exserted beyond its cup. i. G. parviflora. 



Flowers 4"-5" broad ; stigma exserted beyond its cup. 



Flowers red, turning scarlet ; fruit canescent. 2. G. coccinea. 



Flowers white, turning pink ; fruit villous. 3. 



Fruit pedicelled ; flowers racemose. 



Leaves mostly glabrous ; fruit 7" long, glabrous, its stout pedicel club-shaped. 4. 



Leaves densely villous ; fruit 5" long, pubescent, its slender pedicel nearly filiform. 



5- 



I. Gaura parviflora Dougl. Small- 

 flowered Gaura. Fig. 3068. 



Gaura parviflora Dougl. ; Hook. Fl. Bor. Am. i : 

 208. 1832. 



Erect, branched, villous-pubescent with whit- 

 ish hairs, 2°-5° high. Leaves ovate-lanceolate, 

 acute or acuminate at the apex, repand-den- 

 ticulate, narrowed at the base, softly pubescent, 

 i4'-4' long, 4"-i8" wide; spikes elongated, 

 usually densely flowered ; flowers sessile, pink, 

 i4"-2" broad, the ovary and calyx-tube slen- 

 der; fruit sessile, narrowed at the base, 

 4-nerved, obtusely 4-angled, glabrous or nearly 

 so, 3"-4" long. 



In dry soil, South Dakota to Iowa, Missouri, 

 Louisiana, Texas, Mexico, Oregon, Utah and New 

 Mexico. May-Aug. 



