EVENING-PRIMROSE FAMILY 601 



Plant taUer, 1-4 dm. high, often viscid above; capsule about 5 cm. long. 



11. S. chamaenerioides. 

 Petals 5-6 mm. long. 12. S. alyssoides. 



Corolla white to ocliroleucoiis or rose-colored. 



Capsule enlarged at the base, tapering upwards; bark shreddy. 



Plant glabrous; leaf-blades oblanceolate. 2. S. decorticans. 



Plant more or less glandular; leaf-blades ovate. 3. S. Boothii. 



Capsule scarcely enlarged at the base, cylindric; plant pubescent; bark not shreddy. 

 Plant strigose or puberulent. 



Leaves Unear. 7. S. refractum. 



Leaves elliptic, spatulate or lanceolate. 



Petals 1-2 mm. long. 10. S. tortum. 



Petals 5-6 mm. long. 12. S. alyssoides. 



Plant villous. 



Leaf-blades 3-5 cm. long, obovate, sparsely vllloiis; petals 7-8 mm. long. 



13. S. macrophyllum. 

 Leaf-blades 1-2.5 cm. long, densely villous; petals 3-5 mm. long. 



14. S. utahense. 



1. S. andinum (Nutt.) Walp. Small annual; stem 3-10 cm. high, branched, 

 canescent-puberulent; leaves linear or Unear-oblanceolate, 1-3 cm. long, entire, 

 more or less strigose; flowers minute, numerous; tube of the hj'panthium less 

 than 1 mm. long; petals about 1 mm. long; capsule 6-7 mm. long, canescent. 

 Oenothera andina Nutt. Hills: Sask. — Wyo. — Utah — Calif. — Wash. Son. — 

 Submont. IMy-Jl. 



2. S. decorticans (H. & A.) SmaU. Originally described as perennial, but 

 apparently only biennial or annual; stem 2-4 dm. high, sparingly branched, gla- 

 brous, somewhat glandular-puberulent in the inflorescence; leaves lanceolate or 

 oblanceolate, 2-6 cm. long, entire or denticulate; tube of the hypanthium about 



4 mm. long; petals white or cream-colored, turning pink, 3-4 mm. long; capsule 

 about 2 cm. long, 2 mm. thick, more or less curved and twisted. Gaura decorti- 

 cans H. & A. 0. gauriflora T. & G. Sandy places: s Utah — Ariz. — Calif. 

 Son. — Suhmont. Ajj-Je. 



3. S. Boothii (Dougl.) Walp. Annual; stem in age glabrate, shining, with 

 white shredd}' bark; leaves petioled; blades ovate, dentate, acute or acuminate, 

 glabrous above or nearly so, hirsute beneath, 2-3 cm. long; tube of hypanthium 



5 mm. long, glandular-pubescent; petals 4-5 mm. long; capsule 1-1.5 cm. long, 

 1.5-2 mm. thick at the base. 0. Boothii Dougl. Gravelly hills: Wash. — Ida. 

 — Nev.^ — Calif. Son. Je. 



4. S. parvulum (Nutt.) Walp. Slender annual; stem 5-10 cm. long, branched; 

 leaves narrowly linear, almost filiform, entire, 1-3 cm. long, less than 1 mm. wide; 

 tube of hypanthiiun 1.5 mm. long; petals 2-3 mm. long; capsule linear-cyhndric, 

 2-2.5 mm. long, 1 mm. thick, erect, straight^ glabrous. 0. parvula Nutt. Sandy 

 plains and rocky hills: Wyo. — Utah — Ida. Son. — Submont. ISIj'-Je. 



6. S. flexuosum A. Nels. SmaU annual; stem 1 dm. high or less, with few 

 branches; leaves narrowly linear, entire, 2-3 cm. long, about 1 mm. wide; tube 

 of hypanthium 1.5 mm. long; capsules linear-cylindric, 2-3 cm. long, S-curved. 

 S. contortum flexuosum A. Nels. Dry soil: Wyo. — Utah. Son. Je. 



6. S. strigulosum Fisch. & Mey. Annual; stem 1-3 dm. high, branched 

 near the base, with spreading or ascending branches; leaves linear or oblong, 

 1-3 cm. long, 1-3 mm. wide, in depauperate specimens narrow and subentire; 

 tube of hji^anthium 2 mm. long; petals 3—4 mm. long; capsule hnear-cjdindric, 

 1 mm. thick, 2-3 cm. long, ascending, only slightly curved. 0. strigulosa T. & G. 

 Sandy places: B.C. — Ida.- — Cahf. Son. ]\Iy-Jl. 



7. S. refractum (S. Wats.) SmaU. Annual; stem erect, diffusely branched, 

 2—4 dm. high, somewhat glandular-puberulent; leaves linear or narrowly hnear- 

 lanceolate, 2-5 cm. long; tube of the hypanthium about 4 mm. long; petals 

 cream-colored, 5-6 mm. long: capsule slender, 2-3 cm. long, more or less twisted, 

 abruptly reflexed. O. refracta S. Wats. Arid regions: s Utah — Ariz. So7i. 



8. S. pubens (S. Wats.) Rydb. Annual; stem 1-3 dm. high; leaves linear, 

 entire or rarely minutely denticulate, 1-3 cm. long, 1-2 mm. ■wide; tube of hy- 

 panthium 1-1.5 mm. long; corolla 3—4 mm. long; capsule linear-cylindric, 2-3 

 cm. long, 1 mm. thick, spreading at the base, arching upwards. (?) S. filiforme 

 A. Nels. Dry places: Ida.— w Colo.— Ariz.— Calif.— B.C. Son. My-Jl. 



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