10 



MUTANTS AND HYBRIDS OF THE OENOTHERAS. 



elliptic, or slightly broadened upwards, unevenly repand-denticulate 

 and mostly rather jagged-toothed near the base, the petioles relatively 

 stout. 



Adult plant (Pis. IV and V). Plant luxuriant, mostly i meter 

 tall, or less. Stem slightly uneven, but scarcely channeled, hirsute, 

 with spreading-ascending somewhat rigid hairs, copiously branched 

 throughout, the lower branches decumbent, the upper ones spreading 

 or curved upward ;* leaves very numerous, 1.5 to 2 dm. long near the 



base of the stem ; blades 

 elliptic-oblanceolate to 

 elliptic-lanceolate; 

 shallowly but rather 

 prominently toothed, 

 and often j a g g e d - 

 toothed near the base, 

 acuminate, those of the 

 upper cauline leaves 

 mostly elliptic, acute, sessile, or nearly 

 so; bracts mainly lanceolate, narrowed 

 or rounded at the base ; conic por- 

 tion of the bud 14 to 18 mm. long, 

 finely pubescent, the free tips of the 

 sepals about 2 mm. long ; hypanthium 

 2 to 3 cm. long, 5 to 6 mm. wide at 

 the mouth, nearly terete, sparingly 

 pubescent or glabrate ; sepals 15 to 

 20 mm. long, much shorter than the 

 tubular portion of the hypanthium, 

 the free tips 4 to 5 mm. long; petals rather delicate, 12 to 16 mm. 

 long, truncate or slightly emarginate at the apex; filaments 8 to 10 

 mm. long; anthers 7 to 8 mm. long ; pistil shorter than the stamens ; 

 stigmas 4 to 5 mm. long; capsule 3 to 3.5 cm. long, 7 to 7.5 mm. in 

 diameter at the thickest point, finely pubescent, slightly curved, 

 markedly narrowed at the apex. (PL VI.) 



It is to be seen from the above description that 0. biennis is 

 capable of self-fertilization by reason of the superior length of the 

 stamens, a fact that was demonstrated in the experimental grounds. 

 To secure purely fertilized seeds it was only necessary to inclose the 

 inflorescence in a parchment bag during the opening of the flowers. 



JH ig. 1. 



-Onayra biennis seedling three 

 months after germination. 



*Plants growing in thickets are more spindling and have the lower tranches 

 suppressed, while the young rosettes are luxuriant, with broader leaves, under 

 such circumstances. 



