Berberis
aquifolium Pursh,
B. nervosa
Pursh, B. repens Lindl.
Standardized Common
Name: Oregon Grape
Other Common Names: Oregon Barberry,
Oregon Grape Holly
Family: Berberidaceae
Taxonomy: As broadly defined, Berberis
includes about 500 species. It has been divided by some authorities into two
genera, Berberis and Mahonia. These do not appear to be clearly
differentiated or natural groups, so are seldom separated by modern
taxonomists. Mahonia is still recognized in much nontaxonomic
literature, where commonly encountered synonyms for the above species are M.
aquifolium (Pursh) Nutt., M. nervosa (Pursh) Nutt., and M.
repens (Lindl.) G. Don. Berberis repens and B. aquifolium
were once treated as varieties of a single species and are similar except in
size, the former being much smaller.
Description: Evergreen shrubs,
often low or creeping, sometimes erect and 2 m tall or more (never in B.
repens). Leaves alternate, pinnately compound with terminal leaflet
stalked, lateral leaflets sessile, pointing towards leaf apex; terminal leaflet
3–9.5 cm long (variable among and within species), lateral leaflets all similar
in size or the lower leaflets largest; texture usually thin and flexible,
occasionally thick and stiff; bases asymmetrical; margins dentate, with teeth
spine-tipped, number of teeth per side variable, at least 6 (occasionally 5 in B.
aquifolium). Inflorescences racemose, terminal, crowded, many-flowered.
Flowers yellow, 3–8 mm in diameter; sepals 6, quickly lost; petals 6, producing
nectar; stamens 6; ovary compound, 1-styled. Fruit a berry, blue, glaucous,
juicy, usually oblong-ovoid, 6–11 mm long, few-seeded.
The
three official species differ in vegetative morphology:
|
|
B. aquifolium
|
B.nervosa
|
B.repens
|
|
Number of lateral leaflets
|
2–4
pairs
|
4–10
pairs
|
(1–)2–3
pairs
|
|
Lateral
leaflet shape
|
Broadly
lanceolate to lanceolate-elliptic or narrowly ovate
|
Lanceolate-ovate
to ovate
|
Ovate
or elliptic, sometimes broadly
|
|
Lateral
leaflet apices
|
Acute
to obtuse or rounded
|
Acute
to acuminate
|
Rounded
to obtuse or broadly acute
|
|
Leaflet
surfaces
|
Both
surfaces glossy, smooth
|
Both
surfaces dull, smooth; upper surface somewhat glaucous
|
Dull
and often papillose below, dull and glaucous or rarely glossy above
|
|
Lateral
leaflet venation
|
1
or 3 basal veins
|
4–6
basal veins (midrib and weaker secondary veins)
|
1
or 3 basal veins
|
Parts in Commerce: Rhizome and root
Identification:
- Long,
cylindrical, sometimes branching, bearing occasional rootlets
- Mostly
(3–)5–10(–15) mm in diameter; largest pieces at top of rootstock may be up
to 4.5 cm in diameter, often somewhat knotty or contorted
- Outer bark
yellowish brown to olive, longitudinally wrinkled with small cracks, often
becoming scaly
- Fracture hard
- In
cross-section, root has brownish-green or brown, easily separating,
sometimes thick and lumpy cork; thin yellowish or pale brown ring of
pericycle and phloem; large yellow wood containing numerous narrow rays of
xylem and narrow, sometimes curving parenchyma rays (annular rings may be
visible in older material)
- Rhizome in
cross-section similar, having a broad ring of yellow xylem with a
radiating appearance and a yellow, sometimes off-center pith
- Wood becomes
darker yellow when moistened
- Taste bitter
- Chewing colors
saliva yellow
Adulterants: According to
Youngken, not more than 5% of aboveground stems should be allowed. Stem bark
may be pale yellow or grayish or purplish brown, and often peels off in long
strips. Stem wood may be white rather than yellowish.
References:
Piper CV. The identification of Berberis
aquifolium and Berberis repens. Contrib U. S. Natl Herbarium.
1922;20:437–452.
Whittemore AT. Berberis. In: Flora of North
America Editorial Committee, eds. Flora of North America, vol. 3.
New York, NY: Oxford University Press; 1997:276–286.
Youngken HW. Text-Book of Pharmacognosy, 5th ed. Philadelphia, PA: The
Blakiston Company; 1943:339–340.
Figure 12: a, Berberis aquifolium rhizome cross-section; b, small rhizome of
B. repens.
