200 ONAGRACEAE 



long ; stamens somewhat unequal ; style exceeding corolla ; stigma globose ; capsule linear, com- 

 monly refracted or spreading and straight or curved, even coiled, 3-5 cm. long, generally not 

 beaked ; seeds pale, linear, 1 mm. long. 



Open places, Lower Sonoran Zone; deserts from southern California to Arizona and southern Utah. Type 

 locality: near the Colorado River. March-May. 



18. Oenothera chamaenerioides A. Gray. Willow-herb Primrose. Fig. 3425. 



Oenothera chamaenerioides A. Gray, Smiths. Contr. 5': 58. 18S3. 

 Sphaerostigma chamaenerioides Small, Bull. Torrey Club 23: 189. 1896. 

 Sphaerostigma erythrum Davidson, Bull. S. Calif. Acad. 1: 118. pi. 9. 1902. 



Erect annual, 1-5 dm. tall, usually branching near the base, the stems slender, often reddish, 

 lower portions glandular-puberulent, upper strigillose and glandular-puberulent. Leaf-blades 

 thin, glabrate, 4-8 cm. long, ovate-lanceolate to lanceolate, entire, with petioles 1-3 cm. long, in 

 inflorescence reduced to linear bracts; inflorescence a corymbose raceme, elongating in fruit 

 to 2 dm.; hypanthium 2.5-3 mm. long; sepals lance-ovate, 2.5 mm. long; petals white, often 

 reddish in age, about 3 mm. long ; stamens subequal ; capsule terete, linear, divaricately spread- 

 ing, scarcely if at all beaked, 25-50 mm. long ; seeds pale, linear, about 1 mm. thick. 



Open places in the desert, Lower Sonoran Zone; southern California to St. George, Utah, and EI Paso, 

 Texas. Type locality: near El Paso. March-May. 



19. Oenothera minor var. Cusickii Munz. Cusick's Primrose. Fig. 3426. 



Oenothera minor var. Cusickii Munz, Bot. Gaz. 85: 240. 1928. 



Annual, more or less canescent-strigillose throughout, scarcely if at all glandular, stems 

 simple and erect or usually with several subequal ascending stems, somewhat reddish, slender, 

 5-30 cm. high, with epidermis only tardily exfoliating. Basal leaves largest, the blades spatulate 

 to oblanceolate to elliptic-ovate, subentire, 5-25 mm. long, with petioles almost as long, upper 

 leaves reduced; flowers borne singly in almost all the leaf-axils, the upper being grouped in a 

 spicate inflorescence; hypanthium 1 mm. long; sepals 1 mm. long; petals yellowish, 1-1.2 mm. 

 long ; stamens unequal ; capsule 10-25 mm. long, more or less contorted, gradually narrowed 

 from the base, 10-18 mm. long, often beaked; seeds narrowly obovoid, somewhat angled, grayish, 

 1 mm. long. 



Dry slopes, Upper Sonoran Zone; eastern Washington to adjacent Oregon and Idaho. Type locality: Mal- 

 heur River, Oregon. May-July. 



The typical species, with flowers twice the size, ranges to the east from Idaho and Nevada. 



20. Oenothera nevadensis Kell. Nevada Primrose. Fig. 3427. 



Oenothera nevadensis Kell. Proc. Calif. Acad. 2: 224. fig. 70. 1863. 

 Sphaerostigma nevadense Heller, Muhlenbergia 6: 51. 1910. 



Annual, glabrate, forming a simple erect tuft, 2-5 cm. tall, or with several naked prostrate 

 branches 3-10 cm. long with terminal tufts of leaves and flowers. Leaves narrowly oblanceolate, 

 10-35 mm. long on petioles of about same length; flowers white, diurnal ; hypanthium 3 mm. long, 

 sparingly pubescent; the petals 3.5-5 mm. long; capsules 10-12 mm. long, 1.5-2 mm. thick, 

 quadrangular with ridge running along middle of each face, swollen at base, narrowed toward 

 slender beak, coiled and twisted, usually crowded; seeds pale gray, 1 mm. long, linear-obovoid. 



Depressions, Upper Sonoran Zone; Washoe and Ormsby Counties, Nevada, and apparently adjacent Cali- 

 fornia. Type locality: not given. May-June. 



21. Oenothera alyssoides Hook. & Arn. Alyssum-Iike Primrose. Fig. 3428. 



Oenothera alyssoides Hook. & Arn. Bot. Beechey 340. 1838. 

 Sphaerostigma alyssoides Walp. Rep. 2: 78. 1843. 

 Sphaerostigma implexum A. Nels. Bot. Gaz. 52: 267. 1911. 



Annual, usually branching from base, central stem erect, others ascending and curved at tip, 

 bright green, minutely pubescent, rather slender, 5-35 cm. tall. Leaves bright green, oblanceo- 

 late to ovate-lanceolate, 15-40 mm. long, entire or remotely denticulate, the lowermost with 

 petioles of about same length, upper leaves gradually reduced, subsessile ; hypanthium 2-3 mm. 

 long, glabrous within; sepals 4—5 mm. long; petals white, often drying yellowish, 4-5 mm. 

 long; stamens unequal; style glabrous, about as long as petals; capsule 15-25 mm. long, thick- 

 ened at base, gradually attenuate toward beak-like tip, much coiled or only curved seeds pale, 

 linear-obovoid, minutely cellular-pitted. 



Dry plains of eastern Oregon and adjacent Idaho. Type locality: "Pine Creek, Snake County." June-July. 



Oenothera alyssoides var. villosa S. Wats. Proc. Amer. Acad. 8: 591. 1873. (Sphaerostigma a!\ssoir^cs 

 var. macrophyllum Small, Bull. Torrey Club 23: 192. 1896; Sphaerostigma utahense Small, op. cit. 191.) 

 Grayish in aspect, with canescent or villous hairs throughout; petals white, often drying pinkish; hypanthium 

 4-8 ram. long, pubescent within; style pubescent about the base; capsules often merely curved. Dry plains and 

 slopes. Upper Sonoran Zone; east to the Sierra Nevada, California, from Lassen County to Inyo County; east 

 to Utah and northern Arizona. Type locality: near Salt Lake, Utah. 



