Acacia - Wattles - Akasíutré - Mímósa - Gul blóm - Skrauttré - Garðskálaplanta

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• published: 20 Apr 2014
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Acacia - Acacia spectabilis - Akasíutré. Mudgee Wattle- Acacia spectabilis - is an erect or spreading shrub, endemic to Australia. Alternative common names include Glory Wattle, Pilliga Wattle and Golden Wattle. It grows to between 1.5 and 4 metres metres high and has pinnate leaves. The bright-yellow globular flowerheads appear in axillary racemes, mostly between July and November in its native range. These are followed by thin leathery pods which are 4--17 cm long and 10--19 mm wide. See more: http://en.wikipedia.org/wiki/Acacia_spectabilis Australian species are usually called wattles, while African and American species tend to be known as acacias. Acacia known commonly as acacia, thorntree, whistling thorn, or wattle, is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, described by the Swedish botanist Carl Linnaeus in 1773 based on the African species Acacia nilotica. Many non-Australian species tend to be thorny, whereas the majority of Australian acacias are not. The genus Acacia previously contained roughly 1,300 species, about 960 of them native to Australia, with the remainder spread around the tropical to warm-temperate regions of both hemispheres, including Europe, Africa, southern Asia, and the Americas. Acacias in Australia probably evolved their fire resistance about 20 million years ago when fossilised charcoal deposits show a large increase, indicating that fire was a factor even then. With no major mountain ranges or rivers to prevent their spread, the wattles began to spread all over the continent as it dried and fires became more common. 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, or even purple (Acacia purpureopetala) or red (Acacia leprosa (Scarlet Blaze)). Acacia flowers can be distinguished from those of a large related genus, Albizia, by their stamens, which are not joined at the base. Also, unlike individual Mimosa flowers, those of Acacia have more than ten stamens. Acacia seeds can be difficult to germinate. Research has found that immersing the seeds in various temperatures (usually around 80°C (176°F)) and manual seed coat chipping can improve growth to around 80%. See more: http://en.wikipedia.org/wiki/Acacia Nineteen different species of Acacia in the Americas contain cyanogenic glycosides, which, if exposed to an enzyme which specifically splits glycosides, can release hydrogen cyanide in the "leaves". This sometimes results in the poisoning death of livestock. 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. The tree gains its importance from the description of the burial of Hiram Abiff, who provided some of the builders for King Solomon's Temple in Jerusalem. Egyptian mythology has associated the acacia tree with characteristics of the tree of life, such as in the Myth of Osiris and Isis. (There is a Sanskrit word, akasha, which means aether or spirit.) Á júratímanum (fyrir 208-144 miljón árum) er Ástralía talin hafa verið hluti Suðurmeginlands, sem var kallað Gondwana. Það náði yfir núverandi Suður-Ameríku, Afríku, Indland Madagaskar, Nýju-Kalsedóníu, Nýja-Sjáland og Suðurskautslandið. Seint á þessu tímabili rifnaði þessi landmassi sundur og fór að reka líkt og ísbreiður, sem brotna upp. Því er álitið, að upprunalegan gróður Ástralíu sé að rekja til þessa risastóra, forsögulega meginlands. Bæði núverandi gróðursamfélög og steingervingar á framangreindum meginlöndum og eyjum eru skyld og stundum næstum einsleit, þótt vissulega hafi þau þróast hvert á sinn hátt miðað við umhverfi og aðstæður. Dæmi um þetta eru beyki- (Nothofagus), barrtrjáa- (Podocarpaceae) og fræberandi tegundir ((Myrtaceae, Proteaceae, Stylidaceae, Epacridaceae, Restionaceae o.fl.) Tröllatrén eru mest áberandi í augum gesta. Þau flokkast í rúmlega 400 tegundir mismunandi stærða, allt frá því að vera lægri en mannhæð upp í stærstu plöntur jarðar. Vistkerfi þeirra eru jafnmismunandi og tegundafjöldinn, allt frá regnskógum upp í snjóasvæði og inn á jaðra eyðimarka. Akasíutré hafa gengið í gegnum svipaðar breytingar og aðlögun. Sjá meira: http://www.icelandonline.is/ferdaheimurisl/astralia_flora.htm