A STUDY OF HYBRIDS BETWEEN NICOTIANA 
BIGELOVII AND N. QUADRIVALVIS* 
E. M. EAST 
(WITH FOUR FIGURES) 
The genus Nicotiana was divided by G. Don into four sections: 
Tasacum, Rustica, PETUNIODES, and Porrpiciia. This classifica- 
tion has been followed in all Nicotiana monographs down to the 
present day, although several species have been shifted back and 
forth. The section PorrmiciiA is based upon Nicotiana quad- 
rivalvis Pursh (Lehm. Gen. Nic. Hist. pl. 4) and its variety 
multivalvis Gray (Syn. Fl. N. Amer. 2%: p. 253). (See Comes’ 
Monographie du genre Nicotiana. Naples. 1899, p. 54.) The 
experiments on N. Bigelovii Watson and NV. quadrivalvis Pursh 
reported in this paper show that such a section is unwarranted. 
The writer began an extended series of genetic investigations 
upon the species of the genus Nicotiana in 1907 at the Connecticut 
Agricultural Experiment Station. Seed of several species was very 
generously given by Professor O. Comes of Naples, Italy, through 
Dr. D. G. Fartrcuitp of the United States Department of Agricul- 
ture; by Dr. A. SpLeNDoRE of Scafati, Italy; and by Professor W. 
A. SETCHELL? of the University of California. The source of the 
seed from Italy is unknown to me, but several of the species obtained 
from Professor SETCHELL were‘only one or two generations removed 
from the wild. The following description of NV. quadrivalvis Pursh 
is taken from Gray’s Synoptical flora of North America. 
N. QUADRIVALVIS Pursh. A foot high, rather stout, more or less viscid 
pubescent, low-branching: leaves oblong or the uppermost lanceolate and the 
lower ovate-lanceolate, acute at both ends, mostly sessile (3-5 in. long); the 
* Contribution from the Laboratory of Genetics, Bussey Institution of Harvard 
University. No. 14. 
? IT had the pleasure of describing some of my experiments with Nicotiana hybrids 
to Professor SeTcHELL, during his visit to Boston last winter. He said at that time 
that he had reached conclusions similar to mine in regard to N. Bigelovii and N. 
quadrivalvis, although what experiments he has made I am unable to state. 
243] [Botanical Gazette, vol. 53 
