PREFACÉ. ^ 
tumn; and also plentifully, even by self-sowri 
seed ;—but the seed when produced i in the neigh- 
bourhood of kindred species, is ever liable to be 
adulterated through the means of busy insects, or 
the passing gales; and is therefore on no account 
to be preferred where an increase can be had by 
parting the roots, . Indeed, from the numerous 
mongrels already in our gardens, this tribe, like 
some few others, threatens very soon to bid defi- 
ance even to the eyes of a botanist, to discrimi- 
nate amongst its contaminated seedlings, which 
are constantly arising, however distinct the parent 
plants may be, and how widely soever separated 
in a state of nature by intervening cóuntries or 
continents, or even half the globe. 
"The seeds when sown, require only shade. and 
moisture, and the common protection from wee 
frost, worms, insects, slugs, and snails, &c. ; un 
will lower the second year after sowing, and some- 
times sooner. But as they usually vegetate very 
freely, n" and Mapaploniing are frequently 
Me o near Hull, "er 
: — 1817. Ea. 
Es i$: An * d certat denotes such plants 
are ave been first specifically de- 
veribed y the dier; j or by him first shown. to 
r authors; or, at the 
es first. admitted " the present writer s di- 
tinet, 'epeties) since the days of Tintátin: 
