2 University of California Publications in Botany [Vol. 5 



The sources of supply for seeds have been collectors and 

 botanical gardens. From various collectors, seeds of wild species 

 have been obtained, particularly of the Pacific Coast and of 

 Texas. From the botanical gardens of Europe and America I 

 have been able to obtain seeds of most of the cultivated species, 

 and from the various divisions of the Bureau of Plant Industry 

 I have been able to obtain seeds of many of the cultivated 

 varieties and forms of Nicotiana Tahacum. 



At first the study was largely systematic and morphological, 

 with the entirely and naturally to be expected result that it was 

 found that very considerable confusion existed in the naming of 

 the diff'erent plants. Some two or three years were devoted to 

 growing almost everything that could be obtained and attempting 

 to straighten out the nomenclature, which has been a matter of 

 no little difficulty. The only recent revision is that of Comes 

 (1899) and this has been used, so far as it clearly applies, in 

 unravelling the tangle of names current in trade and in the 

 botanical gardens. 



After careful growing and selecting, about seventeen species 

 as generally recognized, remain, together with some well-marked 

 varieties. It seems best to enumerate and discuss these to some 

 extent, in order that a basis may exist for more exact knowledge 

 of the work in the following pages. I hope, also, to be able 

 to return to these later and publish a critical discussion of them. 



Comes in his "Monographic du genre Nicotiana" (1899), 

 divides the genus into four sections, viz., I, Tahacum ; II, Rus- 

 tica; III, Petunioides, and IV, Polidiclia. This classification is 

 that of G. Don (1838) as well as of Dunal (1852). For reasons 

 which will be discussed in a later paper, it seems that IV, viz., 

 Polidiclia, cannot be separated from III, viz., Petunioides. Con- 

 sequently I have retained I, II, and III, and will discuss the 

 stock of species and varieties collected in the Botanical Garden 

 of the University of California under these three sections. (At 

 the very time of writing this, I receive East's paper (1912) en- 

 titled "A Study of Hybrids between Nicotiana Bigelovii and 

 N. quadrivalvis." He also gives very convincing reasons for 

 combining the sections Petunioides and Polidiclia) . 



