1. WOOD
• Wood is a hard, fibrous structural tissue found in
the stems and roots of trees and other woody
plants.
• It is defined as all that portion of the axis of
woody plants lying inside the cambium line.
• It consists mainly of secondary xylem, which may
occasionally enclose in the center a very small
amount of primary xylem and pith.
• The wood is obtained from the trunks, branches
or roots of the dicots or coniferous trees or
shrubs.

2. Kinds of Wood
I. Sapwood or Alburnum
Sapwood usually occurs as whitish or
pale in color, containing living
cells and reserve food materials,
i.e. starch. It is originally
functioning both as conductive
and as support.
II. Heartwood or Duramen
• This is usually dark colored,
almost black,
• it consists of dead cells where the
food materials disappear, the
parenchyma becomes more
lignified.
• filled with substances such as oils,
gums, resins and tannin
compounds.
• the woods used in medicine are
composed of heartwood.

3. • - The wood or xylem consists of:
1. - Fibers
2. - Tracheids
3. - Vessels
4. - Wood parenchyma
5. - Medullary rays

4. Forms of Thickenings
1.Annular: the thickening is in the
form of rings at intervals along
the inner surface of the cell-wall.
2.Spiral vessels: the walls show a
spiral line of thickening.
• The above mentioned two types
of vessels are found only in the
protoxylem.
3.Reticulate vessels: the thickening
of the walls takes the form of a
network.

5. 4. Pitted vessels:
• the whole of the wall is
thickened except of numerous
small areas or pits which are
usually bordered, which
constitute the dominant kind
of vessels present in
commercial dicot woods.
5. Scalariform vessels:
• the pits are sometimes
transversely elongated and
separated from each other by
bar-like thickening, giving a
ladder-like appearance.

8. Tyloses
•Tyloses are balloon-like swellings, produced by the bulging of the
cell-wall of the adjacent wood parenchyma or medullary ray cell,
through the pit openings, into the cavity of the vessel.
•Tyloses are usually devoid of contents occasionally starch granules,
crystals, resin or gum may be present.
•formation of tyloses may be induced in many plants by wounding
and thus by pruning, tyloses are produced to block the cut vessels.

9. Annual Rings
• Owing to the climatic variations, the
vascular cambial tissue, in most
woody plants, exhibits a periodical
seasonal activity.
• This result in the formation of
alternate cylindrical layers of wood
appearing in cross section as rings,
each corresponding to one year
growth, thus called annual rings.

10. Quassia Wood ‫المـر‬ ‫الخشب‬
• Botanical Origin
Quassia is the dried wood of the trunk and branches
of Picrasma excels (Sw.) Planch. (Jamaica Quassia)
or of Quassia amara L. ( Surnam Quassia), Family
Simaroubaceae.

11. Active Constituents
1- The bitter amaroids (0.75%): Quassin, Isoquassin and Neoquassin.
• Quassin (of commerce) is a molecular complex of picrasmin, quassin
and neoquassin.
Uses
1- A non-astringent bitter tonic so can be used safely with iron preparation.
2- It is also used to destroy parasites, and given as enema, to expel thread
worms.
3- Large quantities of Quassia are used in horticulture for the destruction
of aphids.
4- Extracts known as "Quassin" are used to impact a bitter flavor to food
and alcoholic products.
5- It may be safely used in all cases of lack of appetite such as anorexia
nervosa.
6- Externally as lotion, it may be used against lice infestations.

12. • Special Chemical Tests
Boil gently about 0.5 g of powdered Quassia + 5 ml
of alcohol for few minutes  filter  add to the
filtrate 2 drops of phloroglucin + 4 ml of conc.
hydrochloric acid  rose red color is produced
within few minutes.

13. Sandal wood ‫الصندل‬ ‫خشـب‬
Botanical Origin:
It is obtained from Santalum album L., Family:
Santalaceae.
Active Constituents:
Volatile oil, the chief constituents of the oil is the
alcohol Santalol.
Uses:
1- A source of volatile oils.
2- The oil is a stimulant and disinfectant.