Dictionary Definition
acacia n : any of various spiny trees or shrubs
of the genus Acacia
User Contributed Dictionary
see Acacia
English
Pronunciation
- Rhymes with: -eɪʃə
Etymology 1
From acacia < sc=polytonic < sc=polytonic.Noun
- botany countable A shrub or tree of a species that belongs to the genus Acacia, is believed to belong to this genus, or once belonged to the genus.
- pharmacy uncountable The inspissated juice of several species of Acacia.
- Term applied especially to the wattle tree.
Synonyms
Translations
shrub or tree
- Finnish: akasia qualifier official, akaasia qualifier unofficial
- French: acacia
- Portuguese: acácia
- Russian: акация
inspissated juice of Acacia
in Australia, the wattle tree
Etymology 2
UnknownNoun
See also
References
- 1913}}
Dutch
Etymology
FromExtensive Definition
Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of
the family Fabaceae, first
described in Africa by the
Swedish
botanist Carolus
Linnaeus in 1773.
Acacias are also known as thorntrees or wattles,
including the yellow-fever acacia and umbrella acacias.
There are roughly 1300 species of Acacia worldwide,
about 960 of them native to Australia, with
the remainder spread around the tropical to warm-temperate regions
of both hemispheres, including Africa, southern Asia, and the Americas.
Classification
The genus Acacia is apparently not monophyletic. This
discovery has led to the breaking up of Acacia into five new genera
as discussed in list
of Acacia species. In common parlance the term "acacia" is
occasionally misapplied to species of the genus Robinia, which also
belongs in the pea family.
Robinia
pseudoacacia, an American species locally known as Black
locust, is sometimes called "false acacia" in cultivation in the United
Kingdom.
Geography
The southernmost species in the genus are Acacia dealbata (Silver Wattle), Acacia longifolia (Coast Wattle or Sydney Golden Wattle), Acacia mearnsii (Black Wattle), and Acacia melanoxylon (Blackwood), reaching 43°30' S in Tasmania, Australia, while Acacia caven (Espinillo Negro) reaches nearly as far south in northeastern Chubut Province of Argentina. Australian species are usually called wattles, while African and American species tend to be known as acacias.Acacia
albida, Acacia
tortilis and Acacia iraqensis can be found growing wild in the
Sinai
desert and the Jordan
valley. It is found in the savanna vegetation of the tropical
continental climate.
Description
The leaves of acacias are compound pinnate in general. In some species, however, more especially in the Australian and Pacific islands species, the leaflets are suppressed, and the leaf-stalks (petioles) become vertically flattened, and serve the purpose of leaves. These are known as phyllodes. The vertical orientation of the phyllodes protects them from intense sunlight, as with their edges towards the sky and earth they do not intercept light so fully as horizontally placed leaves. A few species (such as Acacia glaucoptera) lack leaves or phyllodes altogether, but possess instead cladodes, modified leaf-like photosynthetic stems functioning as leaves.The small flowers have five very small
petals, almost hidden by the long stamens, and are arranged in
dense globular or cylindrical clusters; they are yellow or
cream-colored in most species, whitish in some, even purple (Acacia
purpureapetala) or red (Acacia
leprosa Scarlet Blaze).
The plants often bear spines, especially those
species growing in arid regions. These sometimes represent branches
which have become short, hard and pungent, or sometimes
leaf-stipules. Acacia
armata is the Kangaroo-thorn of Australia and Acacia
erioloba is the Camelthorn of Africa.
Symbiosis
In the Central American Acacia sphaerocephala, Acacia cornigera, and Acacia collinsii (collectively known as the bullthorn acacias), the large thorn-like stipules are hollow and afford shelter for ants, which feed on a secretion of sap on the leaf-stalk and small, lipid-rich food-bodies at the tips of the leaflets called Beltian bodies; in return they add protection to the plant against herbivores. Some species of ants will also fight off competing plants around the acacia, cutting off the offending plant's leaves with their jaws and ultimately killing it, while other ant species will do nothing to benefit their host.Pests
In Australia, Acacia species are sometimes used as food plants by the larvae of hepialid moths of the genus Aenetus including A. ligniveren. These burrow horizontally into the trunk then vertically down. Other Lepidoptera larvae which have been recorded feeding on Acacia include Brown-tail, Endoclita malabaricus and Turnip Moth. The leaf-mining larvae of some bucculatricid moths also feed on Acacia: Bucculatrix agilis feeds exclusively on Acacia horrida and Bucculatrix flexuosa feeds exclusively on Acacia nilotica.Acacias contain a number of organic
compounds that defend them from pests and grazing
animals.
In Burma, Laos and Thailand, the
feathery shoots of Acacia pennata (common name cha-om, ชะอม and su
pout ywet in Burmese) are used in soups, curries, omelettes, and stir-fries.
Honey made by
bees using the acacia flower
as forage
is considered a delicacy, appreciated for its mild flowery taste,
soft running texture and glass-like appearance. Acacia
honey is one of the few honeys which does not crystalize.
Acacia is listed as an ingredient in Fresca, a citrus soft drink,
and Barq's
root
beer, as well as in Läkerol
pastille candies, Altoids mints, and
Wrigley's
Eclipse chewing
gum.
Gum
Various species of acacia yield gum. True gum arabic is the product of Acacia senegal, abundant in dry tropical West Africa from Senegal to northern Nigeria.Acacia
arabica is the gum-Arabic tree of India, but yields a
gum inferior to the true gum-Arabic.
Medicinal uses
Many Acacia species have important uses in traditional medicine. Most all of the uses have been shown to have a scientific basis, since chemical compounds found in the various species have medicinal effects. In Ayurvedic medicine, Acacia nilotica is considered a remedy that is helpful for treating premature ejaculation. A 19th century Ethiopian medical text describes a potion made from an Ethiopian species of Acacia (known as grar) mixed with the root of the tacha, then boiled, as a cure for rabies. An astringent medicine, called catechu or cutch, is procured from several species, but more especially from Acacia catechu, by boiling down the wood and evaporating the solution so as to get an extract.Ornamental uses
A few species are widely grown as ornamentals in gardens; the most popular perhaps is Acacia dealbata (Silver Wattle), with its attractive glaucous to silvery leaves and bright yellow flowers; it is erroneously known as "mimosa" in some areas where it is cultivated, through confusion with the related genus Mimosa.Another ornamental acacia is Acacia
xanthophloea (Fever Tree). Southern European florists use
Acacia baileyana, Acacia dealbata, Acacia pycnantha and Acacia
retinodes as cut flowers and the common name there for them is
mimosa.
Ornamental species of acacia are also used by
homeowners and landscape
architects for home
security purposes. The sharp thorns of some species deter
unauthorized persons from entering private properties, and may
prevent break-ins if planted under windows and near drainpipes. The
aesthetic characteristics of acacia plants, in conjunction with
their home security qualities, makes them a considerable
alternative to artificial fences and walls.
Paints
The ancient Egyptians used Acacia in paints.Perfume
Acacia farnesiana is used in the perfume industry due to its strong fragrance. The use of Acacia as a fragrance dates back centuries. In The Bible, burning of acacia wood as a form of incense is mentioned several times.Symbolism and ritual
The Acacia is used as a symbol in Freemasonry, to represent purity and endurance of the soul, and as funerary symbolism signifying resurrection and immortality.Several parts (mainly bark, root and resin) of
Acacia are used to make incense for rituals. Acacia is
used in incense mainly in India, Nepal, Tibet and China. Smoke from
Acacia bark is thought to keep demons and ghosts away and to put the gods in
a good mood. Roots and resin from Acacia are combined with rhododendron, acorus, cytisus, salvia and some other components
of incense. Both people and elephants like an alcoholic beverage
made from acacia fruit.
Tannin
The bark of various Australian species, known as wattles, is very rich in tannin and forms an important article of export; important species include Acacia pycnantha (Golden Wattle), Acacia decurrens (Tan Wattle), Acacia dealbata (Silver Wattle) and Acacia mearnsii (Black Wattle).- Inner bark
Black Wattle is grown in plantations in South
Africa. Most Australian acacia species introduced to South
Africa have become an enormous problem, due to their naturally
aggressive propagation. The pods of Acacia
nilotica (under the name of neb-neb), and of other African
species are also rich in tannin and used by tanners.
Wood
Most acacia species are used for valuable
timber; such are Acacia
melanoxylon (Blackwood) from Australia, which
attains a great size; its wood is used for furniture, and takes a high
polish; and Acacia omalophylla (Myall Wood, also Australian), which
yields a fragrant timber, used for ornamental purposes. Acacia seyal
is thought to be the Shittah-tree
of the Bible,
which supplied shittim-wood. According to the Book of
Exodus, this was used in the construction of the Ark
of the Covenant. Acacia koa from the
Hawaiian
Islands and Acacia
heterophylla from Réunion island
are both excellent timber trees.
In Indonesia (mainly
in Sumatra)
and in Malaysia (mainly
in Sarawak)
plantations of Acacia
mangium are being established to supply pulpwood to the paper
industry.
Phytochemistry of Acacia
Alkaloids
As mentioned previously, Acacias contain a number
of organic
compounds that defend them from pests and grazing animals. Many
of these compounds are psychoactive in humans. The
alkaloids found in
Acacias include dimethyltryptamine
(DMT), 5-methoxy-dimethyltryptamine
(5-MeO-DMT) and N-methyltryptamine
(NMT). The plant leaves, stems and/or roots are sometimes made into
a brew together with some
MAOI-containing plant and consumed orally for healing,
ceremonial or religious uses. Egyptian
mythology has associated the acacia tree with characteristics
of the tree of
life (cf. article on the
Legend of Osiris and Isis).