DAHLIA. 181 
all the varieties known in the gar- 
dens have been raised ; as it seeds 
freely, and varies very much when 
raised from seed. In 1802, D. 
frustranea, Ait., (D. coccinea, Cav.,) 
wus introduced from France, in 
which country it had been raised 
from Mexican seeds. A few varie- 
ties have been raised from this kind, 
but they are much smaller than 
the others. It is rather remarka- 
ble, that the two species do not 
hybridize together; and that D. 
supérflua, or variabilis, should pro- 
duce flowers of colours so different 
as crimson, purple, white, yellow, 
orange, and scarlet, without hybri- 
dization. Among all the colours, 
however, displayed by these varie- 
ties, no flowers have yet appeared 
of blue, and comparatively few of a 
pure white. These two species, 
and their varieties, were the ouly 
Dahlias known in English gardens 
for many years; as, though a few 
kinds were introduced from time to 
time from France and Spain, yet as 
they did not hybridize with the oth- 
ers, and were rather more tender, 
they were not generally cultivated, 
and appear to have been soon lost. 
Most of these have, however, been 
re-introduced from Mexico, with 
several new species, within the last 
few years ; and there are now ten 
or twelve distinct species, besides 
innumerable varieties of D. varid- 
bilis, to be procured in England. 
The most remarkable of the new 
species is the tree Dahlia, D. excélsa, 
which is said to grow in Mexico 
thirty feet high, with a trunk thick 
in proportion. ‘The name of Geor- 
gina was applied to the Dahlia by 
Willdenow; because the word Dah- 
lia was thought to bear too close a 
resemblance te the word Dalea, 
which had been previously given 
by Thunberg to a smalj leguminous 
genus. As, however, the words 
DAHLIA. 
has recommended that the name 
Dahlia shall be retained, and most 
botanists of the present day have 
followed his recommendation. The 
name Georgina was given in honour 
of Georgi, a German botanist, who 
resided for several years at St. Pe- 
tersburg. 
The Dahlia is a tuberous-rooted 
plant, which is propagated either by 
seeds, or division of the root. The 
seeds are chiefly used for raising 
new sorts; and they should be 
treated like tender annuals, being 
sown on aslight hotbed in February 
or March, and planted out in May. 
The plants rarely flower the first 
year, but the tubers will form in the 
course of the summer, and may be 
taken up in autumn with those of 
the old plants. When the plants 
are propagated by division of the 
root, care must be taken that each 
piece has a bud attached to it. 
These buds, or eyes, as the garden- 
ers call them, are not scattered all 
over the tuber, like those of the po- 
tato, but collected in a ring round 
the collar of the root. These eyes, 
when the root is in a dry state, are 
sometimes scarcely perceptible ; and 
to discover them, nurserymen often 
plant their Dahlia-roots in a hotbed, 
‘to start the eyes,” as they call it ; 
that is, to force the latent buds suffi- 
ciently forward to show where they 
are situated, before they divic he 
roots for the purpose cf forming 
plants. Sometimes the eyes do not 
form a ring. round the collar or 
crown of the root, but a considera- 
ble portion of it is without any buds. 
These parts, when divided from the 
rest, are called blind tubers; and 
though, if put into the ground, they 
will live for several years, sending 
out abundance of fibrous roots every 
year, no gardener has yet been able 
to induce a blind tuber to form an 
eye, or to send up a shoot. This 
are both spelled and pronounced | peculiarity should be kept in mind 
cuaerently, Professor De Candolle| by all novices in floriculture; as 
16 
