Genetical Studies on Oenothera. V. 189 



he gniwii in tlie hope of fiiiclin^^ a sufficient range of variation to give 

 material for selection towards the hirge-flowered Lamarckiana of DE 

 Veies. I expect to publish the results of these studies in a later paper 

 accompanied ])y illustrations and giving- detailed comparisons between 

 the parent plants, and of the hybrids with the parent plants and with 

 Lamarckiana. 



In this paper I shall consider the hybrids only in comparison with 

 one another and with the parents, making clear certain sharp distinc- 

 tions between the reciprocal crosses and certain marked patroclinous 

 tendencies towards the parents. 



First a brief description of Oenothera franciscana Bartlett will 

 be given that its points of contrast \vith 0. biennis Linnaeus, described 

 on pages 174 and 175 of tills paper, may be made clear. 



Cotyledons. S — 1) mm. long, broadly elliptical and long-petioled. 



Young rosettes. A close cluster of elliptical leaves not so broad as tliose of biennis 

 and with longer petioles. 



Mature rosettes. .S'5 — 4'5 dm. broad. Leaves relatively longer and not so broad as 

 those of biennis, less strongly crinkled but like biennis forming a close cluster. 

 A marked tendency to send out side branches before the central shoot. 



Mature plants. 1 — 1'2 m. high, taller than biennis. Central shoot surrounded by nume- 

 rous long side branches from the rosette as in biennis. Stems with a heavy 

 pilose covering, the long hairs arising from red papillae in sharp contrast to the 

 sparsely pilose and wholly green stems of biennis. 



Foliage. Leaves elliptical, narrower and shorter than those of biennis, irregularly 

 toothed, crinkled. 



Inflorescence. Bracts '/s — V2 length of mature buds, somewhat narrower than those of 

 biennis. Younger buds projecting beyond the bracts. 



Mature buds. 8'5 — 9 cm. long. Cone .3'2 — .3'.5 cm. long, strongly 4-angled. Sepals 

 tinged with red in broad lengthwise bands and never wholly green as in biennis 

 Sepal tips .5 — 6 mm. long and thick. Pubescence of sepals and ovaries very 

 heavily pilose and puberulent. Papillae on ovary colored red. 



Petals. .3 — 3'5 cm. long, light yellow. 



Stigma lobes. 4 — ö mm. long, from .5 — 7 mm. above the tips of the anthers. 



Capsules. 2'8 — 8 cm. long, heavily pilose and puberulent. 



The reciprocal crosses between biennis and franciscana were 

 grown in 1913. From 652 seeds of franciscana X biennis a total of 

 328 seedlings were obtained, the seed pans being kept 4 — 7 weeks. 

 About '/2 of the seedlings and rosettes were strongly etiolated and weak, 

 ranging through intermediates of light green to rosettes of normal color 

 and strength. I have never before met with a large group of etiolated 

 rosettes in an Fi generation, and have no explanation of the pheno- 

 menon to suggest unless it be possible that the pollen of biennis sent 



