A NEW DAHLIA OF INTEREST 
TO PLANT BREEDERS 
Kk. SAFFORD, of the Bureau 
of Plant Industry, has pub- 
. lished in a recent issue of the 
Journal of the Washington 
Academy of Sciences (July 19, 1919), 
descriptions of two new dahlias from 
Guatemala, one of which, D. popenovit, 
should be of more than ordinary in- 
terest to plant breeders who are work- 
ing with this genus. According to Mr. 
Safford, this species is probably an 
ancestor of the cactus-flowered dahlias, 
a group derived from Dahlia juarezi. 
The latter species is a hybrid, supposed 
to have originated naturally in Central 
America through the crossing of 1D). pop- 
enovu and some other species. 
Mr. Safford, who is at work on a 
revision of the cultivated dahlias with 
a view to determining their botanical 
relationships, writes: 
“Tn nearly all the monographs on the 
genus Dahlia hitherto published, the 
different varieties have been grouped 
from the horticulturalist’s point of view. 
according to the forms of the flowers, 
under such headings as ‘single, duplex, 
anemone-flowered, collarette, pompon, 
fancy, decorative, peony-flowered, and 
cactus dahlias,’ without identifying the 
single-flowered forms with botanical 
species (except perhaps in Dahlia 
coccinea and Dahlia imperialis) or at- 
tempting to connect the ‘duplex’ and 
double forms with their primitive single 
ancestors. It is very probable that the 
types upon which several species have 
been based were hybrid plants. Dahlia 
pinnata itself, the type of the genus, 
was probably a hybrid. In the Index 
IXewensis its name is discarded as a 
synonym for the subsequently described 
D. variabilis. In the same way the 
handsome Dahla juaresu with large 
double heads composed of strap-shaped 
florets having their edges turning back- 
ward, in sharp distinction to the 
involute or quilled floets of the artifi- 
cial-looking “‘pompon dahlias’ and the 
broad, flat-rayed heads of the ‘century’ 
type of modern catalogues, is also to 
be regarded as a hybrid. Dahlias with 
flowers identical in form with the type 
of Dahlia juaresii, the ancestor from 
which the ‘cactus dahlias’ of our gar- 
dens have sprung, are no longer called 
‘cactus dahlias’ by specialists, but 
‘cactus hybrids.’ One of the ancestors 
of Dahlia juarezu must have been a 
single-flowered species, with eight 
revolute ray-florets. Such a plant has 
recently been discovered in the moun- 
tains of Guatemala.” 
Mr. Safford describes this species, 
D. popenovii, as a plant about one meter 
high, with slender, purplish stems, the 
leaves simply pinnate (except perhaps 
the lower ones), and the flower-heads 
about 3 inches broad with eight slender, 
revolute ray florets, bright scarlet or 
cardinal in color. It differs from the 
closely allied Dahlia coccinea in the 
shape of the ray florets and the scales, 
and in the character of its leaves. 
This new dahlia is being propagated 
by the Office of the Foreign Seed and 
Plant Introduction of the Bureau of 
Plant Industry, by which it was intro- 
duced from Guatemela. 
