Mr. J. Miers on the genus Polydiclis. 361 
in the mouth, with five erect teeth, and enclosing a nearly glo- 
bular berry 4 lines in diameter. 
PoLyDICcLis. 
The Nicotiana quadrivalvis of Pursh, and the Nicotiana multi- 
valvis of Prof. Lindley, have long been known as anomalous spe- 
cies, which Don placed in his section Polydiclia of that genus, 
and I propose to adopt that name, or rather its more correct de- 
rivation, for a distinct genus, in order to embrace these plants, 
which are distinguished from Nicotiana by the different struc- 
ture of the fruit and other characters. The first-mentioned plant 
is a native of Missouri, where it is said to be cultivated as tobacco ; 
it was introduced into England in 1811 and figured in the 
‘Botanical Magazine.’ The latter species was first cultivated in 
England in 1826 and figured in the ‘ Botanical Register.’ They 
both differ from Nicotiana mm their globular, three or more celled 
ovarium, with placente projecting from the axis into the middle 
of the cell, where they become thickened and ovuligerous. The 
capsule is globular, often very large, umbilicate at the apex, three- 
to eight-grooved, with as many corresponding septicidal valves, 
which break away from the shriveled dissepiments. In Poly- 
diclis multivalvis, which has a six- or eight-celled ovarium, the pla- 
centz are often pluripartite i in each cell, and as they become in- 
crassated, the fruit according to Dr. Lindley presents a series of 
external spurious cells around the true seminal cavities. Its 
generic name is derived from zroAvs, multus, diKALs, valva, on 
account of the greater number of the valves and divisions of its 
capsule. 
Porypic cis (gen. nov.).— Calyx globoso-tubulosus, 10-16-nervis, 
5-8-dentatus, dentibus valde acutis, ineequalibus, erectis, per- 
sistens et augescens. Corolla tubo cylindrico, 15- vel pluri-ner- 
vio, basi ventricoso, oe 2—-3-plo longiore, limbo late campa- 
nulato, ad medium 5—6-fido, laciniis expansis, obtusiusculis, 3- 
nervis, venisque anastomosantibus pictis. Stamina 5- 6, i in- 
eequalia, inclusa, medio corollz inserta, filamenta tubo 3-plo 
breviora, filiformia, anthere ovate, 2-lobe, lobis lberis, appo- 
sitis, rima exteriori dehiscentibus. Ovarium globosum, disco 
carnoso insitum, 3 ad 6-loculare, placentis ex angulis promi- 
nentibus in centro loculorum incrassatis, multiovulatis. Stylus 
erectus, inclusus. Stzgma clavatum, 3 ad 6-lobum, lobis ob- 
tusis, expansis, glanduloso-papillosis. Capsula globosa, magna, 
umbilicata, 8-12-sulcata, calyce aucto arcte cincta, 3-pluri- 
loculari, 3-plurivalvis, valvis septicidalibus dissepimentis de- 
mum solutis, seepe locellis aliis spurts exterioribus donata. 
Semina plurima, parva, oblonga, compressiuscula, hilo laterali. 
Embryo intra albumen carnosum leyiter incurvus, radicula te- 
