Gaura. ONAGRACEJE. 233 



11. BOISDUVALIA, Spach. 



Calyx-tube funnelfonn above the ovary, deciduous; the lobes erect. Petals 4, 

 obovate-cuneiform, sessile, 2-lobed, purple to white. Stamens 8, those opposite to 

 the petals shorter ; filaments very slender, naked at base ; anthers all perfect, ob- 

 long, attached near their base. Ovary 4-celled, several-ovuled : style filiform : 

 stigma-lobes short, somewhat cuneate. Capsule membranaceous, ovate-oblong to 

 linear, nearly terete, acute, sessile, dehiscent to the base. Seeds ascending, few 

 (3 to 8) in one row in each cell, ovate-oblong, somewhat angled, smooth. Erect 

 leafy annuals ; leaves alternate, sessile, simple ; flowers small, in leafy simple or 

 compound spikes. (Enothera Boisduvalia, Torr. & Gray, Fl. i. 505 ; Watson, 

 Proc. Am. Acad. viii. 600. 



A small genus confined to Western America, there being two Chilian species in addition to the 

 following. 



1. B. densiflora, Watson. Canescently pubescent and more or less villous, 

 often stout, i to 2 feet high : leaves lanceolate to linear-lanceolate, acuminate, 

 mostly denticulate, 1 to 3 inches long ; the floral leaves usually much shorter and 

 broader : flowers in a usually close terminal spike or numerous short lateral spike- 

 lets : calyx 1 to 3 lines long, about half the length of the petals : capsules ovate- 

 oblong, smooth or slightly villous, 2 to 4 lines long ; cells 3 6-seeded, the parti- 

 tions wholly separating from the valves and adherent to the placenta : seeds nearly 

 or quite a line long. (Enothera densiflora, Lindl. Bot. Reg. t. 1593. Boisduvalia 

 Douglasii, Spach, Monog. Onagr. 80, t. 31, fig. 2. 



From Washington Territory to Monterey (Nuttall), near Fort Tejon (RothrocJc), and in the 

 foot-lulls of the Sierra Nevada to Tuolumne County : near Carson City, Aiidkrson. Very 

 variable. 



2. B. Torreyi, Watson. Villous throughout with short stiffish spreading hairs, 

 rather slender, a span or two high : leaves linear to lanceolate, usually narrow at 

 base, entire or somewhat denticulate, 4 to 9 lines long ; the floral leaves similar 

 and scarcely smaller : flowers in a loose simple spike, very small (a line or two 

 long), purplish : capsules linear, acuminate, 4 to 6 lines long ; cells 6 - 8-seeded, 

 the partitions adherent to the valves : seeds more ovate and smaller, half a line 

 long or less. Gayophytum strictum, Gray, Proc. Am. Acad. vii. 340. (Enothera 

 Torreyi, Watson, 1. c. 



Oregon (Hall) and southward in the Coast Ranges ; New Almaden, Torrey. 



3. B. glabella, Walpers. Glabrous or slightly pubescent, slender, a foot high : 

 leaves ovate to oblong-lanceolate, acute, serrate, a half to an inch long ; the floral 

 bracts scarcely smaller : flowers in a simple spike, shorter than the leaves : petals 

 deep purple, less than a line long : capsules ovate-oblong, 2 to 4 lines long ; parti- 

 tions adherent to the valves : seeds 4 to 6 in each cell, linear-lanceolate, a line long. 



(Enothera glabella, Nutt. ; Torr. & Gray, Fl. i. 505. 



Valley of the Columbia (Nuttall, Hall) ; Truckee and Carson River valleys, Nevada, Bailey, 

 Watson. 



12. GAURA, Linn. 



Calyx-tube prolonged beyond the obconic or clavate ovary ; the 4-parted limb 

 deciduous. Petals 4, with claws. Stamens 8, nearly equal ; filaments furnished 

 with a scale-like appendage on the inside next the base ; anthers oval, versatile. 

 Ovary 4-celled : ovules 1 to 2 in each cell, pendulous : style filiform, hairy be- 

 low : stigma 4-lobed, surrounded by an obscure ring or indusium. Fruit nut-like, 

 indehiscent or splitting at the apex, obtusely 4-angled and ridged upon the sides. 



