EVENING-PRIMROSE FAMILY 593 



9. PHAEOSTOMA Spach. 



Annual caulescent herbs. Leaves alternate, narrow. Flowers in terminal 

 racemes. Hypanthium-tube above the ovary obconic. Sepals 4, reflexed. 

 Petals 4, rhomboidal, with a broad short blade, entire, purple. Stamens 8, all 

 perfect, with hairy scales at the bases. Stigma with broad lobes. Capsule 

 elongate, somewhat fusiform, 4-angled, 4-celled, 4-valved to the middle. Seeds 

 without a coma, obliquely prismatic. 



1. P. rhomboidea (Dougl.) A. Nels. Stem puberulent or glabrous, 3-6 

 dm. high; leaves petioled; blades oblong-lanceolate or oblong-ovate, 3-5 cm. 

 long; petals purple, 5-7 mm. long, short-clawed, the claw often with a tooth on 

 each side; blades rhombic, entire; capsule 15-25 mm. long, 4-angled, nearly 

 glabrous. Clarkia rhomboidea Dougl. Ospianthes gauroides (Don.) Lilia Sandy 

 soil and hillsides: B.C. Mont. Utah Calif. Submont. Ap-Jl. 



10. OENOTHERA L. EVENING-PRIMROSE. 



Biennial or annual stout herbs, with taproots. Leaves alternate, undulate 

 or toothed. Flowers in terminal spikes, nocturnal, from erect buds. Hypan- 

 thium-tube above the ovary funnelform. Sepals 4, reflexed. Petals 4, usually 

 obcordate, yellow, or in age turning purplish. Stigmas with 4 linear lobes. 

 Stamens 8. Capsule usually tapering upwards, 4-celled, loculicidal, 4-valved. 

 Seeds in two or more rows, horizontal. [Onagra Adans.] 



Free tube of the hypanthium 1.5-4 cm. long. 



Petals turning pink or purplish in age, 3-4 cm. long. 



Free tips of the sepals about 4 mm. long; pubescence of the leaves short, that of 



the calyx not very copious. 1. O. Hookeri. 



Free tips of the sepals 2-2.5 mm. long; pubescence of the leaves long and loose, 

 that of the calyx copious. 2. O. hirsutissima. 



Petals not turning pink or purplish in age, less than 3 cm. long. 

 Free tips of the sepals 3 mm. long or longer. 



Spike not conspicuously leaf y-bracted ; bracts lance-linear, none except the 

 very lowest ones exceeding the hypanthium-tube or the fruit in length. 



3. O. subulifera. 

 Spike conspicuously leaf y-bracted ; bracts, even the upper ones, exceeding the 



hypanthium-tube or the fruit in length. 

 Bracts caudate-acuminate, with twisted tips; plant canescent; corolla 



about 15 mm. long. 4. O. Cockerellii. 



Bracts not caudate-acuminate. 



Petals 10-12 mm. long; plant green. 5. O. muricata. 



Petals 20-30 mm. long; plant canescent. 6. O. ornata. 



Free tips of the sepals about 2 mm. long. 



Stem erect; petals 12-20 mm. long. 7. O. strigosa. 



Stem decumbent; petals about 10 mm. long. 8. O. depressa. 



Free tube of the hypanthium 8-15 cm. long. 



Leaves linear, entire. 9. O. longissima. 



Leaves ovate or lanceolate, sinuate-dentate. 10. O. Jamesii. 



1. O. Hookeri T. & G. Biennial, with a taproot; stem 5-10 dm. high, 

 erect, angled, more or less hirsute and canescent; leaves lanceolate, repand-den- 

 tate, hirsute and canescent, 5-20 cm. long; free tube of the hypanthium 3.5-4 

 cm. long; sepals about 3 cm. long, more or less hirsute; petals 3-4 cm. long; 

 capsules 4-5 cm. long, hirsute and more or less canescent. Onagra Macbridei 

 A. Nels. Valleys: Mont. N.M. Calif. B.C.; n Mex. Submont. Mont. Je-S. 



2. O. hirsutissima (A. Gray) Rydb. Biennial, with a taproot; stem 3y6 

 dm. high, grayish pubescent, as well as coarsely hirsute, sometimes almost his- 

 pid; leaves lanceolate or linear-lanceolate, entire, or merely denticulate, 5-10 

 cm. long, densely hirsute; bracts linear-lanceolate, shorter than the hypanthium- 

 tube; free part of the hypanthium about 3 cm. long; sepals about 3 cm. long; 

 petals 3-4 cm. long; capsule 2.5-3 cm. long. Oenothera biennis hirsutissima A. 

 Gray. Valleys: N.M. Colo. Ariz. Chihuahua. Jl-S. 



3. O. subulifera Rydb. Biennial; stem 3-6 dm. high, sparingly hirsute; 

 leaves lanceolate or the lower oblanceolate, densely pubescent, somewhat ciner- 

 eous, 5-15 cm. long, minutely denticulate; free tube of the hypanthium 1.5-2.5 

 cm. long; calyx-lobes about 2 cm. long, sparingly hirsute, somewhat glandular; 

 free tips 3-4 mm. long, slender; petals 1.5-2 cm. long; capsule 2.5-3.5 cm. 



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