Eucalyptus

a large genus of peach and gold, often called eucalyptus trees, evergreen trees, thick bark and long-staying, or smooth and year-on-year shedding. Leaf two types, young leaves without handle and life, mature leaves sickle-shaped or long round. There is volatile aromatic oil. Flowers of both sexes, tube bell-shaped and sub-room, petals and slivers into a cap-like body, male majority, flower medicine heart-shaped or kidney-shaped, straight cracking or hole opening; flower plate exists; sub-room,
2
to
7
room, embryo beads majority.fruit is hidden in a pot-shaped tube or protruding outside the tube; Seeds are mostly, and only a few can be bred. About
600
species, concentrated in Australia and Tasmania.species of eucalyptus trees are very common,
200
years ago the genus of eucalyptus was less than
300
species, and later due to natural hybridization so that the species increased to more than
600
species. The habitat conditions of eucalyptus trees in their origin are not consistent, from the high-temperature tropical to the winter frosty mountains, from the coastal estuary allout to the gravel of the mantle, eucalyptus trees have a strong germination force, which is conducive to afforestation renewal, or for the distillation of essential oils and the use of shrubing operations.widely introduced and cultivated eucalyptus trees in tropical and subtropical regions of the world. China introduced eucalyptus trees nearly
100
years of history, the main tree species are fine leaves, red birber, lemon, birber, large leaf, oblique gum, blue, straight rod blue.eucalyptus tree is famous for its huge trees. The largest king is
100
meters. The wood texture of eucalyptus trees is dense, the material is hard, resistant to insect decay, corrosion resistance, can do advanced doors and windows, furniture and so on. Branches contain a variety of essential oils, their components are eucalyptus, ene, water
scent
oil, resting fennel and pepper ketones, etc. , for medicine, cosmetics and industrial raw materials.classification of eucalyptus trees is more complex.
1933

W
.
F
． Blackley concentrated the work of his foreman and sorted out
8
groups. (1) Giant group (
Macran
-
therae
), (2) kidney group (
Renantherae
), (3) proposed kidney group (
Renan-theroideae
), (4) proposed perforation group(
Portheroidea) e
), (5) Top-hole group (
Terminales
), (6) slimming group (
Graciles
), (7) micro-drug group (

-
theratherae
), (8) wide-drug group (
Platyantherae
). There
3
subgroups and
18
subgroups. It is currently widely used.addition,
R
.
T
． Baker and
H
.
G
． Smith (
1921
) divided the genus into
9
, depending on the composition of volatile essential oils contained in the leaves, which has application value. (1) essentialcontaining terpenes, does not contain water musk oil essentials and eucalyptus alcohols, such as willow
E
.
21 species
saligne
)
21. (2) The main oil containing ene and eucalyptus alcohol, does not contain water musk oil essence and resting fennel aldehyde, such as wild slugs, zebra skins, etc.
49
kinds. (3) containing eucalyptus alcohol, but not much , and there is a resting fennel aldehyde, but no water musk oil essence, such as zebra leaf

10 species. (4) There are 5 kinds of oil essentials, such as honey-flavoured
and
water. (5) containing eucalyptus, ene and resting fennel alcohol, water-scarce fennel oil essence, such as fine leaves, red, birch, etc.
18
species. (6) Contains , eucalyptus alcohol and water musk oil essence, such as the usual
24
species. (7) Water-containing fennel oil essence, eucalyptus alcohol and pepper ketones, such as almonds,
7
species. (8) Watery musk oil essence and pepper ketone, but no eucalyptus alcohol has
11
species. (9) does not belong to the above list of various types, but also does not contain eucalyptus alcohol, there are lemon zest and oblique pulse gum (
E
.
11 species
kiltoniana
)
11.