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Panax
ginseng C. A. Mey.; P. quinquefolius
L.
Standardized Common
Name: Asian
Ginseng; American Ginseng
Other Common Names: Ginseng; Korean
Ginseng, Oriental Ginseng (P. ginseng); Seng (in English meaning P.
quinquefolius, in Chinese a general term for tonic roots)
Family: Araliaceae
Taxonomy: Panax
includes about 11 species of perennial herbs with medicinal roots. Most are
native to eastern Asia, including P. ginseng; two, including P.
quinquefolius, are native to eastern North America. (These two regions have
relatively similar climates, and there are a surprising number of genera that
share this distribution.) Panax ginseng and P. quinquefolius are
very closely related and are similar in appearance. Their root morphology is
variable and overlapping, so that isolated roots of the two plants cannot be
reliably distinguished by morphology alone. The most frequently encountered
synonym for P. ginseng is P. schinseng Nees.
Description: Perennial herb with
short vertical rhizome and long taproot. Taproot tapering or cylindrical,
0.5–2.5(–5) cm in diameter, often branching, yellowish, with slender secondary
roots; adventitious roots often arise from rhizome. Stem erect, to 60 cm high,
unbranching. Leaves 1–6, increasing in number in older plants, whorled,
long-petioled, palmately compound; leaflets 5, the 2 basal leaflets 2–4 cm long
and elliptic to ovate, the 3 central leaflets 4–15 cm long and oblong to
elliptical or slightly obovate; leaflet apices acuminate, bases cuneate to
oblique; margins coarsely serrate with few small hairs (P. quinquefolius)
or finely serrate and hairless (P. ginseng). Inflorescence a simple
umbel, hemispherical, terminal, borne on peduncle 7–20 cm long. Flowers 2–3 mm
in diameter, hermaphroditic; calyx 5-toothed, green; petals 5, creamy, ovate;
stamens 5; ovary inferior, styles 2. Fruit a head of fleshy drupes, each 5–9 mm
in diameter, subspherical, bright red, containing 2 seeds; seeds creamy,
reniform, 5–6.5 mm long.
Parts
in Commerce:
Root with rhizome
Identification:
- Tapering or
cylindrical taproot, 2.5–15(–25) cm long, 0.5–2(–2.5) cm in diameter
- Often curved;
usually with 1-several large branches in lower part, branches forked or
curving outward or parallel and downward-pointing; “classic” form has 2
major branches making root “man-shaped”
- Bearing long
slender rootlets, often numerous if not removed in processing; rootlet
surface bears inconspicuous tubercles or sometimes noticeable warts
- Upper end is
vertical rhizome, 1–4 cm long, usually 0.3–1.5 cm in diameter, curved,
with few stem scars and adventitious rootlets if not removed; uppermost
stem scars circular, the lower often compressed
- Outer surface
yellowish, with numerous shallow circular wrinkles and with fine
longitudinal wrinkles and root scars on lower portion, except in processed
product (typically of lesser quality) that has bark removed, in that case
white with longitudinal striations
- Fracture hard,
starchy; fractured surface yellowish white with brownish cambium layer
- In
cross-section, shows several rows of cork cells; narrow cortex containing
yellow to yellowish-brown or orange resin canals, numerous small patches
of phloem along cambium opposite xylem rays; brownish yellow cambium;
central xylem occupying most of diameter, radiate, with numerous xylem
rays, containing few large vessels, separated by broader, paler rays of
parenchyma
- Odor fragrant,
often weak
- Taste weak, both
sweetish and bitter, mucilaginous
If
the geographic origin of a given root is not known with certainty, it may not
be possible to determine which species it belongs to except by chemical
fingerprinting, as the ginsenosides and other constituents of the two species
differ. P. quinquefolius is typically smaller than P. ginseng and
unprocessed root material has paler yellow outer cork, but there is
considerable overlap. Small rootlets are reliably few in number in P.
quinquefolius, whereas in P. ginseng there may be few or many
present.
Ginseng grown under natural conditions has a
more contorted appearance than cultivated ginseng and is preferred by
traditional Chinese users, who consider it to be more potent. The evidence for
this belief is minimal to nonexistent, and the preference for wild ginseng
threatens native populations with extinction. Several processed forms exist,
including “red ginseng,” which is (or should be) made only from P. ginseng.
Roots are steamed or soaked in a mixture of alcohol and herbs, resulting in a
translucent appearance and red-brown pigmentation throughout. According to
tradition, the roots should be at least 5 years old, and there is some evidence
that roots do become more potent at that age, so very small roots should be
avoided. One stem scar appears for every year of growth after the first, so a
5-year-old root should have 4 stem scars; stem scars are not always easy to
count.
Adulteration: As ginseng is
expensive and increasingly scarce, deliberate adulteration is fairly common.
Other species of Panax are morphologically distinct; ginseng has also
been found to be adulterated with the roots of numerous unrelated plants. All
of these, if sufficiently intact, should be easily distinguishable from
ginseng. (Powdered ginseng has been adulterated with almost everything.)
References:
Court WE. The genus Panax. In: Court WE, ed. Ginseng.
The Genus Panax. Amsterdam: Harwood Academic Publishers; 2000:13–21.
Medicinal and Aromatic Plants—Industrial Profiles, vol. 15.
Fernald ML. Gray’s Manual of Botany, 8th ed. New York: American Book
Company; 1950:1077.
Hu SY. The genus Panax (ginseng) in Chinese
medicine. Econ Bot. 1976;30:11–28.
Pharmacopoeia Commission
of PRC, eds. Pharmacopoeia of the People’s Republic of China, English ed., vol. 1. Beijing: Chemical Industry
Press; 1997:151–153.
Veninga L. The Ginseng Book. Santa Cruz;
1973.
Wen
J. Species diversity, nomenclature, phylogeny, biogeography, and classification
of the ginseng genus (Panax L., Araliaceae). In: Punja ZK, ed. Utilization
of biotechnological, genetic and cultural approaches for North American and
Asian ginseng improvement, Proceedings of the International Ginseng Workshop.
Vancouver: Simon Fraser University Press; 2001:67–88.
Wichtl M, ed. Herbal Drugs and
Phytopharmaceuticals, 3rd English
ed. Stuttgart: medpharm Scientific Publishers and Boca Raton, FL: CRC Press;
2004:255–258.
World Health
Organization. WHO Monographs on Selected Medicinal Plants. Vol. 1. Geneva: World Health Organization;
1999–2002:168–182.
Youngken HW. Text-Book of Pharmacognosy, 5th ed. Philadelphia, PA: The
Blakiston Company; 1943:618–619.
Figure 50: a–b, Panax quinquefolius whole root and
cross-section.
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