EVENING-PRIMROSE FAMILY 603 



Petals 4-6 mm. long; leaves and stem sparingly hairy or glabrate. 



9. C. parviflora. 



Leaves interruptedly pinnate, the larger alternate pairs 12 or more, not reduced. 



10. C. multijuga. 



1. C. pterosperma (S. Wats.) Small. Stem slender, 5-10 cm. high, branched, 

 hirsute; leaves oblong-lanceolate, 1-2 cm. long, entire, hispidulous; tube of 

 hypanthium 1 mm. long; petals obcordate, rose-colored, 1.5-2 mm. long; capsule 

 cylindric-clavate, 12-18 mm. long; seeds 2 mm. long, the margins thin, incurved, 

 cellularly tuberculate. Oenothera pterosperma S. Wats. Foot-hills: Utah Calif. 

 Son. My-Je. 



2. C. scapoidea Nutt. Stem glabrous, 1-3 dm. high, simple or branched 

 at the base; leaves petioled, simple or pinnate, with small lateral leaflets; blade 

 or terminal leaflet ovate or elliptic, 1-4 cm. long, dentate or entire, glabrous, 

 veiny; tube of the hypanthium 2-3 mm. long; petals bright yellow, 3-5 mm. 

 long; capsule 1.5-2 cm. long, 2 mm. thick. 0. scapoidea Nutt. Hills and river 

 banks: Wyo. Colo. Ariz. Calif. Ore. Son. Submont. 



3. C. cruciformis (Kellogg) Howell. Stem 2-4 dm. high, finely puberu- 

 lent or glabrate; leaves interruptedly pinnate; leaflets 5-15, lanceolate or ovate, 

 0.5-4 cm. long, veiny; tube of hypanthium 4-5 mm. long; petals 7-10 mm. long; 

 capsule about 2 cm. long, 2 mm. thick. O. cruciformis Kellogg. Dry regions: 

 Ore. Colo. Ariz. Calif. Son. Mr-Je. 



4. C. brevipes (A. Gray) Small. Stem branched at the base, 2-3 dm. high, 

 usually densely white-hirsute; leaves simple, or pinnate with small lateral leaf- 

 lets; blade or terminal leaflet ovate, 3-5 cm. long, dentate, veined, hirsute; tube 

 of the hypanthium 5 mm. long; petals yellow; capsule spreading on short pedi- 

 cels. 0. brevipes A. Gray. Arid regions: s Utah Ariz. Calif. Nev. Son. 

 Ap-Je. 



5. C. Parryi (S. Wats.) Small. Stem branched, 2-3 dm. high, sparingly 

 ciliate; leaves simple, petioled; blades ovate or oblong-lanceolate, 2-5 cm. long, 

 entire or sinuate, pubescent with scattered long spreading hairs, especially on 

 the veins; free tube of hypanthium 1 mm. long; petals yellow or orange, 6-7 mm. 

 long; capsule 8-12 mm. long, ascending. Clayey hills: s Utah. L. Son. 



6. C. tenuissima (M. E. Jones) Rydb. Stem much branched, 3-10 dm. 

 high; leaves mostly simple; blade lanceolate, sparingly dentate, acute at each 

 end, veiny beneath, sparingly pilose, about 1 cm. long; inflorescence racemes or 

 panicles, axillary, with ascending-spreading branches; tube of the hypanthium 

 about 1 mm. long; petals 2-5 mm. long, yellow; capsule clavate, 4-6 mm. long, 

 on divergent pedicels. 0. tenuissima M. E. Jones. Barren clay soil: Utah. 

 Son. S. 



7. C. Walkeri A. Nels. Stem slender, 1-2 dm. high, minutely glandular- 

 pubescent and with some long white hairs; leaves simple, entire, ovate to oblong- 

 lanceolate, white-hirsute; tube of hypanthium 0.5 mm. long; petals yellow, oval; 

 capsule clavate, 10^14 mm. long, on a filiform spreading pedicel of the same 

 length. Gypsum hills: w Colo. Son. Jl. 



8. C. venosa Nels. & Kenn. Stem 3-5 dm. high, villous, becoming gla- 

 brate in the inflorescence; leaves 1-2 dm. long, interruptedly pinnate; terminal 

 leaflet orbicular or ovate, 2-4 cm. long, finely canescent above, hirsute beneath, 

 veiny, irregularly serrate; the lateral ones smaller and lanceolate; tube of hy- 

 panthium 2.5 mm. long; petals yellow, turning purple, 8 mm. long; capsule 2 

 cm. long, almost glabrous. Canons and river valleys: Nev. Utah. Son. 

 My-Je. 



9. C. parviflora (S. Wats.) Rydb. Annual; stem 2-3 dm. high, glabrous 

 or sparingly pubescent; leaves interruptedly pinnate, glabrous or nearly so; 

 terminal leaflet ovate, 2-4 cm. long, sharply serrate, strongly-veined, the lateral 

 ones lanceolate, smaller; tube of hypanthium 2 mm. long or less; petals light yel- 

 low, 4-6 mm. long; capsule about 3 cm. long, 2 mm. thick. O. brevipes parviflora 

 S. Wats. Arid regions: s Utah Ariz. L. Son. 



9. C. multijuga (S. Wats.) Small. Stem branched, glabrous, 2-3 dm. 

 high; leaves interruptedly pinnate; larger leaflets 12 pairs or more, of nearly 



