120 ^ Rhodora [JULY 
plants similar to this cuneate-leaved form abundant and widespread 
it would be more uncertain, but even in such a case the blunder of the 
ten leaflets ought to settle the question of which to regard as R. Cana- 
densis. 
There are other though probably local forms of unarmed, glabrous, 
high-bush blackberries. Rubus Millspaughii Britton is one, as I 
tried to show in the American Botanist, Nov., 1904, and R. amabilis 
Blanchard (Кнорова, 8: 173) is another. 
R. Canadensis is never absolutely unarmed like R. triflorus Richard- 
son. Even in deep shade there are a few small prickles, and in open sun 
they are often quite noticeable. Neither is the species often perfectly 
glabrous in every part, as will be seen from the description following. 
Runvs Canapensis L., Sp. Pl. 494 (1753). Plants large, erect, 
pyramidal in outline with stout furrowed stems. Glabrous or slightly 
pubescent, glandless. Unarmed or with few short prickles. Flowers 
large and showy on slender pedicels. Leaflets narrow. Fruit rather 
small, sour, in large, open racemes. 
New canes. Stems rather strong, erect, seldom branched, recurved 
above, 4 to 6 ft. high, 5 to 8 ft. long, dark red, glabrous and gland- 
less, well angled and furrowed. Prickles few, straight, small, nearly 
or quite wanting in shade, frequently quite noticeable in open sun, 
very variable; when present a true prickle, rather stout, set perpen- 
dicular to the stem and on its angles only. Leaves large, 5 to 8 ‘in. 
long and wide, 5-foliate, thin, dark green and glabrous on the upper 
surtace, bright green and glabrous or sometimes finely pubescent be- 
neath. Leaflets narrow, long-stalked, taper-pointed, finely and doubly 
serrate-dentate, the middle one ovate, more than twice as long as wide, 
rounded at the base; the others oval and narrower in proportion, the 
side ones slightly rounded at the base and the basal ones cuneate. 
Petioles and petiolules rather stout, glabrous, nearly unarmed, the peti- 
olule of the middle leaflet on large leaves 14 inches long, the side ones 
one-half as long and the basal leaflet short-stalked. 
Old canes. Erect as ever, normally pyramidal in outline, the second 
year’s growth consisting of racemes on the upper part of the stem and 
long, leafy branches resembling new canes below, generally one from 
each old leaf axil but often two. Axis of long leaf-branches nearly 
straight, terete, glabrous, generally unarmed. Leaves 3-foliate or 
some of the outer 5-foliate, resembling those on new canes. Racemes 
4 to 7 in. long; axis nearly straight, stout, glabrous or finely pubescent, 
unarmed; pedicels very slender, set at a great angle to the axis and 
subtended by small bracts; leaves two or three, of fair size, unifoliate 
or trifoliate, leaflets generally narrow; flowers 10—15, appearing about 
the middle of June, large and showy, 1} to 13 in. broad, petals oblong, 
