EVENING-PRIMROSE FAMILY 201 



22. Oenothera decorticans (Hook. & Arn.) Greene. Shredding Primrose. 



Fig. 3429. 



Gaura decorticans Hook. & Arn. Bot. Beechey 343. 1838. 

 Oenothera gauraeflora Torr. & Gray, Fl. N. Amer. 1: 510. 1840. 

 Oenothera decorticans Greene, Fl. Fran. 217. 1891. 

 Sphaerostigma decorticans Small, Bull. Torrey Club 23: 191. 1896. 



Annual, erect, simple or branching below, with the branches ascending or spreading, glabrous 

 to glabrate below, finely pubescent and often glandular above, with shining straw-colored epider- 

 mis which exfoliates readily. Leaves largely near the base, bright green or tinged red, glabrous 

 to finely pubescent, subentire, 2-8 cm. long, with petioles of almost equal length, upper leaves 

 reduced ; inflorescence a fairly compact spike, elongating in fruit to as much as 3 dm. ; hypan- 

 thium 4-6 mm. long ; sepals 4-5 mm. long ; petals white, 5 mm. long, distinctly longer than wide, 

 reddish only in age ; stamens unequal ; capsule subfusiform, thickest in lower half, 2 mm. thick, 

 15^25 mm. long, round in cross section, attenuate into a slender beak, and with simple curve 

 so that the beak spreads away from the stem; seeds ash-colored, linear-obovoid, somewhat 

 angled, minutely pitted, 1 mm. long. 



Loose slopes and disturbed places. Upper Sonoran Zone; Monterey County to Los Angeles County, Cali- 

 fornia. Type locality: Monterey. March-June. 



Oenothera decorticans var. rutila (Davidson) Munz, Bot. Gaz. 85: 245. 1928. (Oenothera rutila David- 

 son, Erythea 2: 62. 1894.) Rather slender-stemmed, considerably diffused with red; flowers small, petals 3.5-4 

 mm' long red, distinctly longer than wide; capsules as in the species. Loose slopes in the mountains about the 

 western end of the Mojave Desert, California. Type locality: San Gabriel Mountains, Los Angeles County. 



Oenothera decorticans var. desertorum Munz, op. cit. 246. More slender than the species, with whiter 

 epidermis on the stems; capsules more slender, 1-1.5 mm. thick at base, more contorted so that tips turn down- 

 ward- flowers as in the species, the petals longer than wide. Open slopes and plains, Lower Sonoran Zone; 

 Mojave Desert of California to Palm Springs, California, and to Rhyohte, Nevada. Type locality: ten miles 

 southwest of Garlic Springs, San Bernardino County, California. 



Oenothera decorticans var. condensata Munz, op. cit. 247. Stems low and thick, usually not over 15-18 

 cm. tall, and with pure white epidermis; petals 4-5 mm. long, suborbicular; capsules woody, much thickened, 

 about 3 mm. at base, quadrangular, and with supplementary ridge down middle of each face. Open plains, 

 deserts of Lower Sonoran Zone; eastern half of the Mojave Desert and the Colorado Desert of California to 

 St. George, Utah. Type locality: Dos Palmos Springs, Riverside County, California. 



23. Oenothera Boothii Dougl. Booth's Primrose. Fig. 3430. 



Oenothera Boothii Dougl. ex Hook. Fl. Bor. Amer. 1: 213. 1834. 

 Sphaerostigma Boothii Walp. Rep. 2: 77. 1843. 

 Sphaerostigma Lemmonii A. Nels. Bot. Gaz. 40: 61. 1905. 



Annual, glandular-pubescent to glandular-villous throughout, erect, 1-4 dm. tall, usually with 

 central stem more prominent than the branches which may spread widely. Leaves ovate to 

 oblong-ovate, fairly evenly distributed, subentire, 2-5 cm. long, with petioles 1-3 crp. additional ; 

 inflorescence racemose-spicate, often quite congested, elongating in fruit; hypanthium 4-8 mm. 

 long; sepals 3-7 mm. long; petals white, pinkish in age, obovate, clawed, 3.5-9 mrri. long; sta-- 

 mens subequal ; capsule 10-15 mm. long, usually ascending in lower half and wath terminal 

 portion spreading but not contorted, thickest near base, 1.5-2 mrn. wide; seeds brown, rhomboid- 

 prismatic, minutely cellular-pubescent, 1 mm. long, gray when immature. 



Dry plains and slopes, mostly in Upper Sonoran Zone; from Walla Walla region, Washington, to eastern 

 California and Utah and Arizona. Type locality: "on the high sandy and gravelly hills of Lewis and Clark s 

 River." June-Aug. 



Oenothera Boothii var. pygmaea (Dougl.) Torr. & Gray, Fl. N. Amer. 1: 510. 1840 (Oenothera pyg- 

 maea Dougl. ex Lehm. in Fl. Bor. Amer. 1: 213. 1834.) Flowers small, hypanthium 1 . 5-2 5 mm. long; 

 sepals 1.5-2.5 mm. long; petals narrowly obovate, 1.5-2.5 mm. long. Similar situations. Upper Sonoran /.one; 

 eastern Washington and Oregon. Type locality: "near the branches of Lewis and Clark s Kiver, lat. 46 nortn. 



24. Oenothera andina Nutt. Plateau Primrose. Fig. 3431. 



Oenothera andina Nutt. in Torr. & Gray, Fl. N. Amer. 1: 512. 1840. 

 Sphaerostigma andinum Walp. Rep. 2: 79. 1843. 



Low, erect, very slender-stemmed annuals, with spreading branches from near the base or 

 above, finely canescent throughout, 2-15 cm. tall and about as broad, lower stem and branches, 

 in all except the smaller plants, rather free of leaves. Leaves alternate, linear to narrowly ob- 

 lanceolate, entire, with short indistinct petioles; flowers axillary in a rather crowded corymb 

 which becomes racemose in fruit; hypanthium 1 mm. long; sepals 1.5 mm. long; petals yellow, 

 1.5 mm. long; stamens unequal; capsule 5-6 mm. long, fusiform, somewhat quadrangular; seeds 

 fusiform, smooth, brown, 0.7 mm. long. . . 



Dried depressions, plains, Upper Sonoran Zone; eastern. Washington to northeastern California, Assiniboia. 

 and Utah. Type locality: "Dry plains in the Rocky Mountams, near the Black-Foot River. May-Jul>. 



Oenothera andina var. Hilgardii (Greene) Munz, Bot. Gaz. 85: 251 1928 (0.n<,t/..ra H.7garrf« 

 Greene, Bull. Torrey Club 10:41. 1883; Sphaerostigma andinum var Hilgardn A. Nels. Bot t,az. 4^0- ^_^- 

 1905.) Flowers larger; hypanthium 1.5 mm. long; sepals 2 mm ; petals 2.5 "'"^/""fc^br°ade■■. capsule 

 mm. In similar situations, eastern Washington. Type locality: "moist alkaline soil of Klickitat SNvale. \\ ash 

 ington." 



Oenothera andina f. tripetala Levi. Mon. Onoth. 182. 1905. (Oenothera andina var. anWa ^I. E. 

 Perk Torreva 32 • 151 193^ ) Like the species, but flowers trimerous and capsules somewhat 3-sided Occa- 

 sional lith species esjecially in easJern Klamath and western Lake Counties, Oregon. Type locality: not given. 



