A MUTATING BLACKBERRY- 
DEWBERRY HYBRID 
L. R. DetyENn 
N.C. Agricultural Experiment Station, West Raleigh. 
UTATIONS among the black- 
M berries and dewberries, with the 
exception of chimeras, have 
been seldom reported. Rubus 
laciniatus Willd. is considered a cut- 
leaved form of the European black- 
berry, R. fructicosus L. Whether it 
originated from a seed or from a mutat- 
ing vegetative bud seems to have never 
been recorded, A cut-leaved variety of 
dewberry of distinctly trailing habits 
has also found its way to the market 
and is grown mostly for ornamental 
purposes, but, like Rubus laciniatus, 
the origin of this dewberry is obscure 
and only a matter for speculation. 
It was the writer’s good fortune to 
discover in the summer of 1915 a 
similarly cut-leaved plant arising as a 
bud mutation from what appears to be 
a wild, natural, blackberry-dewberry 
hybrid. As this hybrid form is very 
common in the vicinity of Raleigh, 
N. C., no especial emphasis need be 
laid on the probable parental species. 
The plant was found growing on a high 
embankment on the railroad right-of- 
way of the spur that enters the State 
Fair Grounds at West Raleigh, N. C. 
The plant when discovered possessed 
two canes, one normal, 7. e,. with entire 
leaflets, and one abnormal, 7. ¢., with 
finely divided leaflets (see Figs. 19 and 
20). As the plant possessed all indica- 
tions of possible propagation by means 
of tip-layers, this method was at once 
resorted to and two new plants were 
thus secured, 
In the late fall of 1915 the mutating 
crown was taken up and planted in the 
station experimental vineyard. The 
two new plants that were secured by 
means of tip-layering were planted in 
the horticultural grounds among five 
varieties of blackberries and three THE CUT-LEAVED MUTATION 
varieties of dewberries. All of 2 the A one-year old cane showing the finely 
plants grew and reproduced the divided divided leaflets. (Fig. 19.) 
92 
