Rubus
idaeus L.
Standardized Common
Name: Raspberry
Other Common Names: American Raspberry
(subsp. strigosus), Red Raspberry
Family: Rosaceae
Taxonomy: Rubus is a
cosmopolitan genus of often thorny shrubs, producing brambles and numerous
edible fruits. One estimate is that there are about 250 species, but species
boundaries in portions of the genus pose a serious taxonomic problem, as both
asexual reproduction and hybridization are common. Rubus idaeus belongs
to Subg. Idaeobatus and ranges from Eurasia to North America. The
strictly North American subsp. strigosus (Michx.) Focke, also known as R.
idaeus var. strigosus (Michx.) Maxim or sometimes as R. strigosus
Michx., is included in commercial Raspberry. Hybridization occurs in North
America between R. idaeus and the Black Raspberry, R. occidentalis
L.
Description: Rhizomatous shrubs
spreading by underground suckers or stolons; stems (canes) biennial, erect, arching,
to 2 m high, usually prickly, bearing fruit in the second year. Leaves
alternate, stipulate, mostly pinnately compound, those of first-year canes with
(1–)3–7 leaflets, those of second-year canes mostly with 3 leaflets; rachis 2–7
cm long, prickly, upper surface furrowed; lateral leaflets sessile, terminal
leaflet petiolate; leaflet blades ovate to oblong or lanceolate-oblong, 3–12 cm
long, terminal leaflet sometimes shallowly lobed; bases cordate, especially on
terminal leaflet, to rounded, often asymmetrical; apices acute to acuminate;
margins serrate or rarely lobed; leaves whitish and woolly-pubescent beneath
with occasional prickles on midrib, nearly glabrous above. Inflorescence a
few-flowered raceme, terminal or axillary, with leafy bracts; flowers
pedicellate, drooping. Hypanthium present, short, flat, not fused to carpels;
receptacle large, convex; calyx lobes 5, lanceolate, usually bristly; corolla
ca. 1 cm in diameter, petals 5, narrow, erect; stamens numerous, white; carpels
numerous, separate. Fruit an aggregate of small 1-seeded drupelets, nearly
globose to broadly conical, red or rarely yellow, hirsute, dispersed as a unit.
Parts
in Commerce:
Leaves
Identification:
- Compound,
usually with 3 leaflets, sometimes with 5–7 or rarely 1; only the terminal
leaflet is long-stalked
- Petiole with
small prickles; upper side grooved
- Leaflets 3–12 cm
long, usually more or less ovate
- Leaflet bases
rounded to subcordate or cordate, often asymmetrical; terminal leaflet
more likely to have a cordate base
- Apices acute to
acuminate
- Margins serrate,
rarely lobed
- Upper surface
green, often pubescent but not densely so
- Lower surface
appearing white, densely pubescent with tangled white hairs, sometimes
with small prickles at base of midrib
- Main secondary
veins parallel on each side of leaflet, running diagonally from midrib to
marginal teeth, occasionally forking; tertiary venation between secondary
veins regular, inconspicuous
- Taste weakly
astringent and bitter
Rubus
fruticosus
L. (Blackberry):
The leaves of the blackberry are also used medicinally and found in commerce.
The blackberry, which belongs to Subg. Rubus, is taxonomically very
complex. It usually reproduces asexually, so that only slightly different
varieties or “biotypes” can remain morphologically distinct, but on occasion
crossbreed to create new biotypes. Practically every European variant, no
matter how minute, has been described as a species or “agamospecies” at least
once or twice. By one estimate over 650 species of blackberry exist in Europe
alone (and over 2000 species names have been published), almost all segregated
from R. fruticosus. Other treatments reduce this to a slightly more
reasonable number of several dozen “circle-species,” but these have no
biological meaning. R. fruticosus, which makes up most of the commercial
blackberry market, is used in a collective sense and refers to most of the
blackberries (the present work favors this approach). Within this great number
of biotypes, all characters may be variable, including those of the stems,
flowers, and fruits as well as those of the leaves. The leaves bear
considerable resemblance to those of R. idaeus; their general features
are as follows:
- Leaves palmately
compound, sometimes with lateral leaflets divided; leaflets usually 5–7,
occasionally 3
- Leaflets sessile
or short-stalked; terminal leaflet often distinctive, sometimes with
longer stalk; rarely all leaflets long-stalked
- Stipules small,
linear, attached to base of petiole
- Petiole often
grooved above, often bearing prickles
- Leaflets often
broadly ovate, sometimes obovate or elliptical
- Leaflet bases
cordate, especially on terminal leaflet, to rounded or somewhat
wedge-shaped or rarely truncate
- Leaflet apices
acute to acuminate
- Margins
regularly or irregularly serrate
- Upper surface
green, often somewhat pubescent, sometimes bearing stellate hairs, rarely
woolly-pubescent with gray hairs
- Lower surface
more or less pubescent, often woolly-pubescent with white hairs, but
sometimes almost hairless, often varying on a single plant
- Taste astringent
References:
Heslop-Harrison Y. Rubus. In: Tutin TG, Heywood VH, Burges NA, et al.,
eds. Flora Europaea. Vol. 2. Cambridge: Cambridge University
Press; 1968:7–25.
Weber HE. The present state of taxonomy and mapping
of blackberries (Rubus) in Europe. Acta Bot Fennica.
1999;162:161–168.
Wichtl M, ed. Herbal Drugs and
Phytopharmaceuticals, 3rd English
ed. Stuttgart: medpharm Scientific Publishers and Boca Raton, FL: CRC Press;
2004:526–530.
Figure 61: a–b, Rubus idaeus leaf and close-up, with
exceptional lobing of terminal leaflet; c–d, R. fruticosus leaf and close-up.
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