ON THE TUBER-BEARING SPECIES OF SOLANUM. 489 
A Review of the Tuberibedring Species of Solanum. 
By J. Q. Baxzz, F.R.S., F.LS. 
[Read January 17, 1884.] 
(Puates XLI.-XLVI.) 
THE subjects of the differential characters, the relationship to 
one another, and the climatic and geographical individuality of 
the numerous types of tuber-bearing Solanums are of great 
interest both from a botanical and economie point of view. As 
there are many points which are still to be unravelled, I propose 
in the present paper to pass in review the material whieh we 
possess in England bearing upon the question. It was at the 
instigation of Earl Cathcart that I undertook the inquiry ; and in 
carrying it out I have gone through all the dried specimens at 
Kew, the British Museum, and the Lindley herbarium, have care- 
fully studied the wild types which we grow in the herbaceous 
ground at Kew, and have visited the extensive trial-grounds of 
Messrs. Sutton and Son at Reading, whose collection of culti- 
vated types in aliving state is probably the most complete in 
existence, and to whom I feel much indebted for their kind aid. 
I propose in the first place to deal with the species and varieties 
in detail geographically, then to summarize them from the point 
of view of the systematie botanist, and finally to make a few 
general remarks on the economie bearing of the facts. 
1. CHILI. 
1. SOLANUM TUBEROSUM, Linn.—The following is a descrip- 
tion, made from the living plant, of typical S. tuberosum, as grown 
in the herbaceous ground at Kew :—Rootstock bearing copious 
large tubers. Stems stout, erect, flexuose, much branched, 
1-2 feet long, slightly hairy, distinctly winged on the angles. 
Leaves pseudo-stipulate, a fully developed one about half a foot 
long, with 7-9 finely pilose oblong acute large leaflets, the side 
ones stalked and unequally cordate at the base, the 1-2 lowest 
pairs much dwarfed, leaving a naked petiole about an inch long; 
the rhachis furnished with numerous small leaflets interspersed 
between those of full size. Flowers numerous, arranged in 
compound terminal cymes, with long peduncles ; pedicels hairy, 
articulated about the middle. Calyx hairy, 4-3 in. long; teeth 
deltoid-cuspidate, as long as, or a little longer than, the campa- 
LINN, JOURN.—BOTANY, VOL. XX. 2R 
