ONAGRACEAE (EVENING PRIMROSE FAMILY) 341 



pubescent or villous, especially on the margins and midrib : calyx-tube very 

 long (12-20 cm.), villous as are also its lobes (5-7 cm. long): corolla large and 

 showy: capsule glabrate or villous, sessile, oblong-cylindrical or lance-ovoid, 

 3-4 cm. long, sinuately ridged or low-tuberculate on the sutures. (P. can- 

 lescens Rydb. 1. c.) Colorado and Utah to New Mexico. 



6. Pachylophus marginatus (Nutt.) Rydb. 1. c. 33. 1906. Subcaulescent 

 or stem sometimes 1 or 2 dm. high, from hirsute to villous throughout (in- 

 cluding the capsule): leaves pinnatifid, toothed, or runcinate: calyx-tube 

 about twice as long as its long lobes: petals broad, 4-5 cm. long: capsule 

 lance-ovate, about 3 cm. long, usually conspicuously pediceled, somewhat 

 tuberculate-cristate on the obtuse angles. Probably extending into our range 

 from the northwest. 



8. LAVAUXIA Spach. 



Perennial or annual, usually low acaulescent herbs. Leaves mostly basal; 

 blades pinnatifid. Flowers few. Calyx-lobes narrow. Corolla white, pink 

 or pale yellow. Ovary short, 4-angled; ovules few. Capsule stout, the acute 

 angles sometimes winged above. Seeds few. Oenothera in part. 



Capsule beaked; flowers 3-4 cm. broad . . . . . . 1. L. flava. 



Capsule obtuse; flowers 8-10 cm. broad . . . . . . 2. L. brachycarpa. 



1. Lavauxia flava A. Nels. Bull. Torr. Bot. Club 31: 243. 1904. Stemless 

 perennial (?), nearly glabrous: leaves crowded, oblong-lanceolate, deeply and 

 irregularly runcinate-pinnatifid, 10-25 cm. long: flowers shorter than the 

 leaves: calyx-tube 4-7 cm. long, the lobes about 2 cm. long: petals yellow, 

 invariably turning pink with age and in drying, obovate: stamens shorter 

 than the petals: capsule oblong, narrowly wing-angled, 2-3 cm. long, one third 

 as broad: seeds numerous, cuneate-obovate. Oenothera triloba. Colorado 

 and Wyoming and probably of wider range. 



2. Lavauxia brachycarpa (Gray) Brit. Mem. Torr. Club 5: 235. 1904. 

 Perennial, caespitose, acaulescent or subcaulescent, at first canescent through- 

 out, glabrate with age: leaves ovate to oblong-linear, from nearly entire to 

 lyrate-pinnatifid : calyx-tube 7-14 cm. long, the lobes nearly half as long, 

 reflexed: petals golden-yellow, 3-5 cm. long, somewhat broader: capsule 

 ovate, 2.5-3.5 cm. long, wing-angled. [L. Howardii (Jones) A. Nels. Bot. Gaz. 

 34: 368. 1902.] Nebraska to Nevada and to Texas and New Mexico. 



9. GAURELLA Small 



Low perennial herbs, with wiry, diffusely branched stems. Leaves alter- 

 nate; blades nearly entire or distantly toothed. Flowers axillary, sessile. 

 Calyx-tube slightly dilated at the throat, scarcely as long as its lobes. Petals 

 white or pink, spotted or striped with red. Ovary short; style stout, en- 

 larged above. Capsule sessile, with a curved beak, the faces swollen. Seeds 

 angled, delicately striate. Oenothera in part. 



1. Gaurella canescens (Torr.) A. Nels. Stems 1-5 dm. long, canescent with 

 appressed hairs, the branches decumbent or ascending: leaf-blades lanceolate 

 or linear-lanceolate, 8-16 mm. long, repand-denticulate or entire: corolla white 

 or pink, 18-25 mm. wide; petals obovate, entire: capsules canescent, 8-10 

 mm. long, angled, not winged: seeds angled, slipper-shaped. Oenothera canes- 

 cens Torr. in Frem. Rept. 315. 1845. [G. guttulata (Geyer) Small, Fl. 844. 1903.] 

 Prairies and plains; Colorado, Nebraska, and New Mexico. 



10. GALPINSIA Britton 



Perennial herbs or shrubby plants with much-branched stems. Leaves al- 

 ternate. Flowers yellow, axillary. Calyx-tube slender, longer than the 

 ovary. Ovary 4-celled, elongated; stigma disk-like, entire. Capsules elon- 



