PREFACE. 
Y 
tlie fructification alone, while ours more especially 
looks to the habit.—Háappily, too, such natural 
groups as are here understood, are also usually ac- 
companied by corresponding agreements in the 
parts which compose their fructifications, and from 
which Botanists are enabled to construct their 
technical generical characters: although this (as 
is best known only to those who have longest la-. 
boured at it) is a much. less easy business than 
is commonly imagined; and liable (as the canon 
of Linneus asserts) to a multitude of unexpected 
and interrupting aberratious. These it is the pro- 
vince of the Botanist to overcome. And where 
the knot is too intricate to be at all unravelled— 
he who cuts it in the most ingenious mauner, still 
renders a valuable service to the science. 
In the Dissertation of 1803, Saxifraga sarmen- 
tosa was the only species mentioned as anomalous 
and isolated; or as likely to form a new genus. 
And in 1809, it became actually elevated into orie, 
under the name of Ligularia, by Duval, in his ca- 
talogue of Suceulent Plants in the Gardens of 
Alengon. Since that time, a second species has 
been discovered and introduced into our gardens, 
which is here described by the name of Ligularia 
eninor, which the writer hears is figured in the Bo- 
tanica Cabinet, | but he has not seen it. Previously 
E: the publieation of the above-mentioned Cata- 
, the author of this Essay had in his MS. 
ici this genus Sarmentea, from its strawberry- 
: b2 
nus ;" because the canon of Linnzus alludesto . 
