EVENING-PRIMROSE FAMILY 197 



13. Oenothera graciliflora Hook. & Arn. Slender-flowered Primrose. Fig. 3420. 



Oenothera graciliflora Hook. & Arn. Bot. Beechey 341. 1838. 



Taraxia graciliflora Raimann in Engl. & Prantl, Nat. Pflanzenf. 3': 216. 1893. 



Cespitose annual with slender taproot, plant unbranched and with a single acaulescent tuft, 

 or with several short horizontal branches becoming 1-3 cm. long, finely pubescent to hirsute 

 throughout. Leaves linear to linear-oblanceolate, entire or remotely denticulate, 2-10 cm. long; 

 sterile portion of ovary filiform, 15^0 mm. long; hypanthium proper 2 mm. long; sepals lance- 

 acuminate, 6-;^8 mm. long ; petals yellow, turning red in age, 8-14 mm. long, with a broad shallow 

 apical notch in which is a middle tooth ; stamens unequal ; stigma globose ; capsule ovate-oblong, 

 8yl2 mm. long, coriaceous, 4-angled near base, each angle expanding upward into a broad wing 

 giving the capsule a truncate apex; seeds straw-colored with grayish blotches, obovoid, 1.5-2 

 mm. long, with very minute cellular pitting. 



Grassy slopes and plains, Upper Sonoran Zone; Oregon (Hornbrook and Kirbyville) to southern California 

 (Los Angeles County). Type locality: California. March-May. 



14. Oenothera heterantha Nutt. Northern Sun-cup. Fig. 3421, 



Oenothera heterantha Nutt. in Torr. & Gray, Fl. N. Amer. 1: 507. 1840. 

 Oenothera heterantha var. taraxacifolia S. Wats. Proc. Amer. Acad. 8: 589. 1873. 

 Taraxia heterantha Small, Bull. Torrey Club 23: 186. 1896. 



Acaulescent perennial, with general habit of the next species, but essentially glabrous, though 

 it may be finely pubescent, especially on the leaf-margins. Leaf-blades lanceolate to ovate-lanceo- 

 late, entire or repand-denticulate or sinuate-pinnatifid, especially at base, 3-15 cm. long, narrowed 

 into winged petioles of almost same length ; sepals lanceolate, 5-8 mm. long ; petals yellow, or- 

 bicular-oboyate, slightly notched at tip, 8-10 mm. long ; stamens unequal ; stigma discoid ; capsule 

 oblong-ovoid, relatively smooth, coriaceous, persistent, somewhat 4-angled, pointed above, not 

 concealed among leaf-bases, 12-15 mm. long; seeds oblong, straw-colored, 3 mm. long, with 

 minute cellular pitting. 



Moist grassy places, Upper Sonoran and Transition Zones; eastern Washington to eastern central California 

 (Tulare County), and Rocky Mountains. Type locality: "towards the sources of the Columbia." May-July. 



15. Oenothera ovata Nutt. Sun-cup. Fig. 3422. 



Oenothera ovata Nutt. in Torr. & Gray, Fl. N. Amer. 1: 507. 1840. 

 Taraxia ovata Small, Bull. Torrey Club 23: 185. 1896. 



Acaulescent biennial or perennial, with thick root from the simple or branched crown of 



which arise numerous flowers and leaves. Leaves with lanceolate to lance-ovate blades, usually 



undulate, entire to denticulate or even sinuate, glabrous above, ciliate on margins and on veins 



below, 3-10 cm. long, with petioles of equal or less length ; sterile portion of ovary slender, 



5-10 (18) cm. long, glabrous; hypanthium 3 mm. long; sepals glabrate to pubescent, lanceolate 



to lance-ovate, 7-12 mm. long; petals yellow, obovate to suborbicular, 8-20 mm. long; stamens 



almost subequal ; capsule linear-ovoid, sessile to pedicellate, usually below the surface of the 



ground, torulose, chartaceous, 1-2 cm. long, tardily dehiscent; seeds relatively few, broadly 



oblong-ovoid, brownish or yellowish, with a peculiar shaggy cellular pubescence. 



Open hillslopes, Upper Sonoran Zone; alon^ the coast from Umpqua Valley, Oregon, to Monterey County, 

 California. Type locality : Monterey. March-June. 



16. Oenothera tanacetifolia Torr. & Gray. Pinnatifid Sun-cup, Fig. 3423. 



Oenothera Nuttallii Torr. & Gray, Fl. N. Amer. 1: 506. 1840. Not Sweet, 1830. 

 Oenothera tanacetifolia Torr. & Gray, Pacif. R. Rep. 2: 121. pi. 4. 1854. 

 Taraxia tanacetifolia Piper, Contr. U.S. Nat. Herb. 11:405. 1906. 



Perennial, with thick root and simple or branched crown, glabrate to finely pubescent. Leaves 

 lanceolate in outline, deeply sinuate-pinnatifid. the blades 3-10 cm. long, the numerous segments 

 unequal, acute, entire or toothed, the petioles slender, about as long as blades ; sterile portion of 

 ovary pubescent, slender, 2-10 cm. long; hypanthium proper 3 mm. long; sepals lance-ovate, acu- 

 minate, pubescent, 7-9 mm. long; petals yellow, aging red, narrowly obovate, 10-15 mm. long; 

 stamens unequal ; stigma globular ; capsule rarely developed, pubescent, narrowly ovoid, quad- 

 rangular, torulose, 17-20 mm. long, 5-6 mm. thick, relatively straight; seeds numerous, brown, 

 oblong, slightly curved, carunculate, finely pitted in longitudinal rows, about 2 mm. long. 



Damp grassy places, Upper Sonoran and Transition Zones; eastern Washington to Mono County, Cali- 

 fornia, Idaho, and Nevada. June-July. 



17. Oenothera refracta S. Wats. Refracted Desert Primrose. Fig. 3424. 



Oenothera refracta S. Wats. Proc. Amer. Acad. 17: 373. 1882. 

 Sphaerostigma refractum Small, Bull. Torrey Club 23: 192. 1896. 

 Oenothera deserti M. E. Jones, Contr. West. Bot. No. 12: IS. 1908. 



Annual, 5—40 cm. tall, erect, with few to several divaricately spreading branches, usually 

 glandular-puberulent and somewhat strigillose throughout, the stems slender, commonly red, 

 with epidermis exfoliating in age. Leaves largest near base of plant, but well distributed up to 

 lowest flowers, oblanceolate to lanceolate to oblong-linear, entire to denticulate, 2-5 cm. long, 

 short-petioled to sessile; inflorescence racemose, sometimes paniculate, 5-15 cm. long; hypan- 

 thium 5-6 mm. long; sepals lance-oblong, 5-6 mm. long; petals white, suborbicular, 4-7 mm. 



