1912] Setchell: Studies in Nicotiana 17 



something at a later date. Thus far it has produced both whites 

 and pure yellows. Lock (1909) has made some experiments in 

 crossing N. Langsdorffii and N. alata, with very interesting re- 

 sults as to corolla-shape and color, and also as to color of the 

 pollen. Both the F^ and the Fo generations in Lock's experi- 

 ments presented intermediates. 



X. Langsdorffii var. longiflora Comes is another intermediate 

 sort of variety described by Comes {loc. cit.). I have not had 

 any plants which answer exactlv to his description, but under 



173 



No. 08 U. C. B. G. (cf. plate 19), there appeared yellow-flowered 

 forms (even the inner, or upper, surface of the limb being yel- 

 low) which comes close to it, as do also certain plants cultivated 



70. 



under the number 06 U. C. B. G., which also have given both 

 yellow and white-limbed flowers. All these are being bred in 

 pure line to be reported on later. 



Nicotiana paniculata L. 



This well-known and widely cultivated species has been 



grown in the U. C. B. G. under several different numbers and 



106 

 from several different sources. No. 05 U. C. B. G. is well 



represented in the photograph reproduced in plate 20. It is 

 a spreading plant up to three or four feet high, the panicle 

 being very effuse. The leaves are broad and slightly cordate, 

 moderately long petioled. The flowers are pale yellow and long 

 tubular, being slightly gibbous just below the limb. The limb 

 is narrow, at first concave, but flattened or somewhat reflexed 

 in full anthesis, broadly and very slightly rounded five-lobed. 

 The capsule is narrow. 



This species is reported to have been under cultivation since 

 the middle of the eighteenth century, having been discovered 

 in Peru in 1752. The plant in the Linnaean Herbarium is exactly 

 the one grown in the U. C. B. G. It is said to be used as a tobacco 

 for the pipe, being mild and of exquisite aroma. It remains con- 

 stant when cidtivated, although at times the flowers are curved 

 nearly into a circle. 



