BOTANICAL APHORISMS. 179 
§ 169. 
The Nectarium affords the best generic character. 
When the nectarium, on account of its singular 
figure, distinguishes one flower from another, it 1s 
an excellent character. But it must be remarked, 
that the structure of the nectary must be striking : 
for it would be improper to consider the Arenaria 
peploides as a distinct genus, because there are giands 
in the flower; or to separate the American Tilia, 
(§ 164), from the European, because’ there are 
small scales in the corolla: But if, as in other 
plants, there are nectaria of a cylindrical or filiform 
figure, such a singular structure ought not to be 
overlooked. The rule is not of difficult observa- 
tion, for there are but few exceptions to’it. 
§ 170. © 
The figure of the style and of ihe jilaments affords 
no generic character, except it is very remarkable. 
It often happens, that the figure of the styi¢ and 
of the filaments in some species of a genus is very 
different; that the style and filaments are bent down, 
or are otherwise of a peculiar figure; but this, iA 
general, is of little importance. However, if in 
any genus there is an essential difference in these 
parts, as in Cordia, it deserves particular attention. 
The germen may be supported on a stalk within 
the flower, asin Euphorbia, Passiflora, Helictévis, 
Sterculia, &¢. which is’a striking character ‘not to 
be neglected. Linné was induced by this stalk, 
which is nothing more than an elongation of the re- 
M 2 ceptacle, 
