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MR. F. N. WILLIAMS ON ‘tHE GENUS SILENE., 3 
The question as to whether Silenacew and Alsinacesw should 
be considered as distinct natural orders or as suborders of 
Caryophyllaceze need not be discussed, as it would be outside 
the scope of the present memoir. Caruel, in the continuation of 
Parlatore’s ‘ Flora Italiana,’* substitutes the name Dianthacerwe 
for Caryophyllaces, which is quite feasible, as being founded 
on the best known genus of the order, instead of on the 
somewhat fanciful name of one of the species of that genus, 
widely known under various forms in cultivation, but not very 
widely distributed as an indigenous plant. 
_ The division of the suborder Silene proposed by Alexander 
Braunt (and generally accepted by botanists), on the presence 
or absence of commissural nerves in the calyx, I regard as 
satisfactory and natural; but I would consider this character 
as a secondary factor in the grouping of genera after the 
primary division into the tribes of Dianthese and Lychnidee, 
based on the character of the seeds,—a modification introduced 
by Boissier in his conspectus of the genera in the ‘ Flora 
Orientalis,’ and followed by Willkomm in the ‘ Prodromus 
Flore Hispanice.’ This modification has the further recom- 
mendation of dispensing with the obscure and uncertain 
character of the mode of overlapping of petals in prefloration. 
The mode of overlapping is certainly not constant within the 
limits of the same genus. As to Brauun’s cardinal character 
derived from the nervation of the calyx, it does not seem to be 
absolutely constant. Schott t has shown that in Viscaria alpina 
(z.e., Lychnis alpina, Linn.) the commissural nerves of the 
calyx are wanting, and for this reason he proposed the species 
as the type of an intermediate genus Liponeurwm. The same 
objection was urged against including Cucubalus Pumilio, Linn., 
in Silene, but the nervation of the calyx in this species is at 
best very faint and indistinct, and the rudiments of commissural 
nerves are clearly evident at the base, more especially on the 
inner surface in the dried plant. This latter plant, however, 
shows more affinity with some species of Saponuria than does 
Viscaria alpina, which differs from typical forms of Viscaria 
only in this one characteristic. In comparing Viscaria alpina 
with V. vulgaris (a plant found at low-lying stations), though 
* Vol. ix, p. 239 (1892). 
+ Flora (1843), i, p. 363. 
t Analecta Botanica, i, p. 55. 
