196 ONAGRACEAE 



9. Oenothera primiveris A. Gray. Yellow Desert Evening-primrose. Fig. 3416. 



Oenothera primiveris A. Gray, Smiths. Contr. 5*: 58. 1853. 

 Lavaiixia primiveris Small, Bull. Torrey Club 23: 182. 1896. 

 Oenothera bufonis M. E. Jones, Contr. West. Bot. No. 8: 28. 1898. 

 Lavauxia lobata A. Nels. Bot. Gaz. 47: 429. 1909. 



Apparently annual or winter annual, with long taproot, cespitose, acaulescent or nearly so, 

 occasionally with stems up to 1 dm. long, villous or pilose-pubescent throughout, the leaf-surfaces 

 sometimes glabrate. Leaf-blades oblanceolate in outline, 1-12 cm. long, usually deeply and regu- 

 larly pinnatiiid into lanceolate or ovate lobes which are in turn lobed or toothed, petioles shorter 

 than blades; flowers vespertine; hypanthium 2-6 cm. long; sepals lance-linear, 15-28 mm. long, 

 without free tips ; petals canary yellow, aging orange-red, cuneate-obovate, usually 2-3 cm. long, 

 with a terminal sinus 4-5 mm. deep ; stamens subequal ; stigma-lobes 6-8 mrn. long ; capsule 

 pilose, quadrangular with heavy rib down middle of each face, reticulate, not winged nor tuber- 

 culate, gradually tapering to attenuate apex, 6-8 mm. thick at base, 18-35 mm. long; seeds in 

 2 rows in each cell, brown, somewhat roughened tuberculate, 2 . 5-3 mm. long, with narrow raphal 

 groove. 



Dry plains, Lower Sonoran Zone; deserts from California to St. George, Utah, and El Paso, Texas. Type 

 locality: El Paso. April-May. 



10. Oenothera flava (A. Nels.) Garrett. Dandelion-like Evening-primrose. 



Fig. 3417. 



Oenothera triloba var. ecristata M. E. Jones, Proc. Calif. Acad. II. 5: 681. 1895. 

 Lavauxia flava A. Nels. Bull. Torrey Club 31: 243. 1904. 

 Oenothera flava Garrett, Spring Fl. Wasatch ed. 4. 106. 1927. 



Perennial, with thick taproot, acaulescent or nearly so, glabrate throughout or finely glandu- 

 lar or pubescent about flowers. Leaf-blades oblong-linear to oblanceolate in outline, 3-20 crn. 

 long, 1-2 cm. wide, deeply and irregularly runcinate-pinnatifid, with a broadly winged rachis 

 passing gradually into the lanceolate to lance-linear terminal lobe, petiole slightly winged, 

 shorter than blade; hypanthium slender, 2-12 cm. long; sepals distinct or united in anthesis, re- 

 flexed, lance-linear, green, often drying purplish, 10-18 mm. long, with free tips an additional 

 1-5 mm. long; flowers vespertine, the petals pale yellow, 10-20 mm. long, orbicular-obovate ; 

 stamens subequal ; stigma-lobes 3-4 mm. long ; capsule indurate, ovate, 1-2 cm. long, 4-winged, 

 each wing reticulate-veined, 2-5 mm. wide, especially above, and with a spreading terminal valve- 

 like tooth 0.5-1.5 mm. long; seeds numerous, dark brown, 2 mm. long, minutely granular, 

 cuneate-obovoid, slightly concave with carinate ridge on ventral side, and wing-like margin 

 around the obtuse summit. 



About desiccating depressions, plateau region, high Upper Sonoran and Transition Zones; Shasta, Lassen, 

 Sierra, and Modoc Counties, California, Yakima River, Washington, Saskatchewan to Colorado, northern Mexico, 

 and Arizona. Type locality: Laramie, Wyoming. May-July. 



11. Oenothera leptocarpa Greene. Mustard-like Primrose. Fig. 3418. 



Eulobus californicus Nutt. in Torr. & Gray, Fl. N. Amer. 1: SIS. 1840. 

 Oenothera californica Greene, Pittonia 1: 290. 1889. Not S. Wats. 1876. 

 Oenothera leptocarpa Greene, op. cit. 302. 



Annual, erect, fairly coarse-stemmed, simple or with few stiflf branches ; stems glabrous or 

 glabrate, somewhat glaucescent. Leaves few, largely in basal rosette, these lanceolate in outline, 

 pinnatifid, 5-15 cm. long, dying early, the cauline leaves smaller, remote, uppermost pendulous, 

 the upper stems appearing quite naked ; flowers solitary, not crowded ; hypanthium obconic, 

 1 mm. long, orange and pubescent within and lined with a lobed disk, glabrous to strigillose 

 without ; sepals lanceolate, 5-8 mm. long, glabrous to pubescent, reflexed in anthesis ; petals yel- 

 low or orange, drying pink, frequently with reddish spots at the base, 6-14 mm. long, rhombic- 

 obovate ; stamens of two lengths ; stigma globose ; capsules linear, quadrangular, not contorted, 

 commonly strongly refracted, 3-10 cm. long, about 1 mm. thick, not conspicuously beaked ; seeds 

 obovoid, light brown with purplish dots, minutely cellular-pitted, 1 mm. long. 



Dry banks and disturbed places. Upper Sonoran Zone; cismontane southern California and adjacent Lower 

 California, occasional in Lower Sonoran Zone of Arizona and Sonora. Type locality: San Diego, California. 

 April-May. 



12. Oenothera Palmeri S. Wats. Palmer's Primrose. Fig. 3419. 



Oenothera Palmeri S. Wats. Proc. Amer. Acad. 12: 251, 1877. 

 Taraxia Palmeri Small, Bull. Torrey Club 23: 184. 1896. 



Dwarf, cespitose annual with slender taproot, finely strigillose throughout, forming small 

 acaulescent tufts 2-6 cm. tall, or with several short horizontal branches 2-4 cm. long ; stems 

 pubescent, with loose white exfoliating epidermis and becoming tough and almost woody in age. 

 Leaves linear-lanceolate to -oblanceolate, subentire to minutely denticulate, 2-6 cm. long ; sterile 

 portion of upper part of ovary filiform, 8—18 mm. long; hypanthium proper obconic, 1-2 mm. 

 long ; sepals lanceolate, 2-3 mm. long ; petals yellow, orbicular-obovate, 3-5 mm. long, the flowers 

 apparently diurnal ; stamens of 2 unequal sets ; stigma globose ; capsules crowded, ovate, 5-7 mm. 

 long, coriaceous and tough, 4-angled below, each angle growing into a thick, obliquely truncate 

 wing along the upper edge of which is the line of dehiscence ; seeds smooth, few, brownish, nar- 

 rowly obovoid, 1.5 mm. long, minutely cellular-pitted. 



Open places, LTpper and Lower Sonoran Zones; eastern Oregon to the Mojave Desert, California, and 

 Arizona. Type locality: Arizona. April-May. 



