1. The document discusses several subterranean plant organs including rhizomes, roots, tubers, corms, bulbs, and their distinguishing characteristics. 2. Rhizomes are described as horizontally-growing underground stems that produce shoots and adventitious roots, while roots derive from the radical and grow vertically towards soil and water. 3. Ginger and turmeric are provided as examples of medicinal plants whose rhizomes are used as drugs, with details on active constituents and traditional medical uses.

1. Subterranean organs
Rhizomes and Roots
By:
Dr. Marwa Fayed
(Ph.D)

2. -These organs are collected from perennial
plants to allow storage of the 2ry metabolites
in these organs.
- Subterranean drugs are from:
root origin
rhizome origin
root and rhizomes.

3. Subterranean organs
Stems Roots
-Rhizomes.
-Corms.
-Stem tubers.
-Bulbs.
-Roots.
-Root tubers.

4. A Stem
– is generally considered to be the central axis of the
plant.
– supports the leaves and flowers of a plant.
– has nodes from which new shoots and sometimes
new roots can arise.
– is usually found above-ground, but can be modified
and found below-ground as well.

5. Tubers
• A tuber is an
underground stem that
stores food.
• We know a potato is a
tuber because it has
nodes (eyes) which
produce new shoots.
A potato is a tuber

7. • A corm is a swollen,
vertical stem, solid,
fleshy with a papery
covering.
• Ex:
Gladiolus and Crocus.
Crocus corms

8. Corms: short fat underground
stems

9. Bulbs
• Bulbs come in 2 basic types:
– Tunicate bulbs; onions and tulips are examples.
– Scaly bulbs; tiger and asiatic lilies are examples.

10. Tunicate Bulbs
• Tunicate bulbs have:
– A papery outer covering
called a tunic.
– A compressed, modified
stem with nodes, called a
basal plate.
– Fleshy scales made of
modified leaf tissue.
A tunicate bulb

11. Tunicate Bulbs
Fleshy Scales
Basal Plate
Onion is a tunicate bulb

12. Tunicate Bulbs
• Tunicate bulbs form
“onion rings” when cut
in cross-section.
Onion bulb shown in cross-
section

13. Bulbs
Big buds
on short stems
Adventitious Roots
Succulent
Storage Leaves
Stem

14. Scaly Bulbs
• The other type of true bulb is a scaly bulb.
Scaly bulbs:
– Lack a papery covering (tunic).
– Have a basal plate.
– Have fleshy scales made of leaf tissue.
– Do not form “onion rings” when cut in cross-
section.

15. Scaly Bulbs
Lilium is a scaly bulb

16. Bulb - onion
Tuber - potato
Corm - Crocus
STEMS

17. Rhizomes
• Rhizomes are:
– underground stems.
– horizontally-growing.
– produce shoots and
adventitious roots.
Iris rhizome

18. Rhizomes
• Other plants, like
ginger, produce large,
thick rhizomes called
pachymorphs.
The pachymorph
rhizome of Ginger

20. Root Modifications
• There are 2 basic types of root
modifications:
– Fleshy Tap Roots
– Tuberous Roots

21. Fleshy Tap Roots
• Carrots, beets, and
radishes are examples
of plants forming
fleshy tap roots.
Carrots

22. Tuberous Roots
• Sweet potato is an
example of a tuberous
root.
A sweet potato is a tuberous root

23. Subterranean stem differs from the aerial
stem in the following
1- It bears scale leaves (not foliage)
2- Bears adventitious roots arise from the
nodes.

24. What is the difference between root and rhizome?
The root:
*It is derived from the
radical and grows
towards the soil and
water.
* It has no leaves.
*No nodes and
internodes.
* No buds.
* No chlorophyll.
* Apical growing point
called root-cap.
The rhizome:
-It has nodes and internodes.
-The growing point covered
with scaly leaves and not
root cap.

25. Structure of old root:
1- Cork.
2- Phelloderm.
3- Phloem (1ry and 2ry).
4- Cambium: responsible for
2ry thickening
5- Xylem (1ry and 2ry).
6- No Central pith.
Structure of rhizome:
1- Cork cells (or epidermis or
metaderm).
2- Cortex.
3- Endodermis.
4- Vascular bundles (monocot.
or dicot.).
5- Central pith.
Microscopically

26. T.S of young root

27. • Botanical origin:
• It is the dried rhizome of Zingiber
officinale Roscoe, Family:
Zingiberaceae.
To avoid insect attack Ginger undergo:
- Decorticated, peeled (unbleached).
- Limed ginger (with calcium
carbonate).

28. Methods of Ginger preparation
• Unbleached Ginger:
Dry ginger is produced from the green underground
rhizomes of the plant Zingiber officinale. It is
prepared by peeling off the outer skin and drying in
the sun for about a week. The dry ginger so
prepared is known as "unbleached ginger".
• Bleached Ginger (Jamaica Ginger):
• peeled washed in clean water containing lime
dried in the sun for 5 or 6 days bleached by
washing and dried again for 2 days coated with
CaC03 for protection against insect & larvae.

29. Ginger is an example for monocot rhizome
with sympodial branching.
The drug has aromatic odour and pungent
aromatic taste.
The pungency is destroyed by boiling with KOH
solution (c.f. Capsicum).

30. T.S in Ginger rhizome
Microscopical characters

33. • Color: yellowish-white.
• Odor: agreeable aromatic.
• Taste: agreeable, pungent and aromatic.
Powdered Ginger
Physical characters

34. Powdered Ginger
Septate fiber scitaminaceous starch

35. oleoresin cells

36. Non-lignified xylem vessels
N.B: Absence of scleried cells or calcium oxalate
- scitaminaceous starch
- oleoresin cells

37. Active constituents
• 1- Volatile oil (1-2 %) containing a mixture of over
50 constituents mainly Zingeberine.
- 2- Gingerol
- 3- Zingerone
- 4- Shogaol.
• 5- Starch and mucilage.

38. • Gingerol (Gingerols):
- responsible for the pungency of ginger.
- An oily liquid consisting of homologous phenols.
- Its pungency is destroyed by boiling with 2%
potassium hydroxide.
- pharmacological activities such as antipyretic,
antitussive, hypotensive [5], cardiotonic, antiplatelet,
antiangiogenic, anti-inflammatory, analgesic,
cytotoxic, antitumor, anticancer, antioxidant,
antihepatotoxic, antifungal, cholagogic, and
antiemetic activities (Sujay Rai et al.2006).

39. • Zingerone:
- is pungent but possesses in addition a sweet
odour.
- its pungency is destroyed by prolonged
contact with 5% NaOH.

40. • Shogaol:
- a component of the oil.
- represents the compounds formed by loss of
water from Gingerol.
- not present in the fresh rhizome but its an
artifact during extraction.

41. Actions and Uses
• Nausea and vomiting of different reasons:
- motion sickness
- postoperative nausea
- vomiting in pregnancy
• Carminative and stimulant.
• Stimulate appetite.
• Flavoring agent in food industry.
• metabolic (heating) and circulatory enhancing
agent for weight control.
• Anti-inflammatory agent.

42. Special chemical test
• Sudan III.
• Iodine.
• http://www.globalsciencebooks.info/Online/GSB
Online/images/0812/MAPSB_2(2)/MAPSB_2(2)7
2-78o.pdf
• https://pdfs.semanticscholar.org/feb5/1489784d
880514c34b4050d13415e0950456.pdf

43. Precautions from (AHPA)
( American Herbal Products Association)
• Ginger should not be used by children under 2 years
of age.
• Ginger intake should not exceed 2 to 4 g per day
(excessive doses of the herb may cause mild
heartburn).
• It should not be used during pregnancy.
• People with gallstones should consult a physician
before taking ginger.
• Ginger may have adverse effects on bleeding time
(Asprine-like action).

44. • Botanical Origin:
• It consists of the prepared
rhizomes of Curcuma
domestica Valeton, or
Curcuma longa, Family:
Zingiberaceae.

45. Preparation
• Curcuma rhizomes are collected at the end of
the growing season.
• Cleaned.
• Boiled for some hours.
• Carefully but rapidly dried in open air.

46. T.S in Curcuma rhizome
Microscopical characters

47. Powdered Curcuma
• Physical characters:
- Color: orange yellow to
yellowish brown.
- Odor: slight aromatic.
- Taste: aromatic bitter.

48. Powdered Curcuma
• Masses of gelatinized starch.
• Parenchyama containing oleoresin.
• Cork cells having yellowish brown walls.
• Non-lignified xylem vessels (spiral, sclariform and
reticulate).

49. Active constituents
• 1- Colouring material known as Curcuminoids
mainly Curcumin and smaller quantities of
dicaffeoylmethane.
• 2- Volatile oil (5%) contain sesquiterpenes
(turmerone, Zingiberine), sesquiterpene alcohols
and ketones.
• 3- Arabinose, fructose and glucose.
• 4- Abundant starch grains and often gelatinized.

50. Actions and Uses
• Aromatic stomachic.
• Diuretic.
• Choleretic and strong anti-hepatotoxic action so
used in jaundice and hepatitis.
• Treatment of peptic ulcers.
• Anti-flatulent.
• Dyspepsia.

51. Special chemical test
• 1- Positive results with Sudan III and Iodine.
• 2- place a few drops of a mixture of equal parts of
conc. H2SO4 and alcohol on a slide being against a
white background. Sprinkle a small amount of the
suspected powder into the reagent, the particles
of Curcuma will turn red and the red color
gradually flows into the surrounding liquid.

52. • 3- Stir a small quantity of the suspected powder
into a thin paste with a mixture of ether and
chloroform. Allow the paste to dry on a filter paper
and when dry remove the powder and treat the
remaining yellow stain with hot saturated boric
acid solution, an orange-red color is produced,
turning bluish black upon the addition of ammonia
solution.

53. Contraindications
• Obstruction of the biliary tract.
• cases of gallstones.
• Hypersensitivity to the drug.