North American Plants – Acacia

Name – The name Acacia is derived from the Greek word 'akis' meaning ‘a sharp point’ and relates to the sharp thorned species of tropical Africa and Western Asia that were the only known acacias at that time.

Description – Acacias vary immensely in size and shape from tiny prostrate plants to trees, some of them up to one hundred and twenty feet tall. Acacias are most conspicuous when in flower because, apart from many having a glorious fragrance, the flowerheads, whether balls or spikes, consist of a number of tiny perfect flowers varying from two or three in each head. as in A.myrtifolia, up to more than a hundred in A.anceps.. Flowers occur on single stalks, in clusters, on racemes (as on A.dealbata) or as panicles, which are branched racemes – and they range in colour from lemon to the brightest sunshine yellow.

Origin – The one everybody wants to grow is Acacia Dealbata, otherwise known as mimosa, which is an evergreen tree with fern-like silvery-green foliage and astonishingly fragrant yellow flowers in late winter and spring. Be aware this plant can make twenty-four feet in height with a spread of eighteen feet. Mimosa can do well when planted in full sun, in neutral to acid, well-drained soil where it will remain hardy in all but the most severe winters once it is established. However, it also makes an ideal conservatory plant. Whichever way you grow it, prune lightly after flowering has finished, cutting back shoots that spoil the shape of the tree. In the garden, incorporate lots of well-rotted garden compost into the planting hole and stake firmly. To grow in a pot, plant in a loam-based potting compost and keep in a sunny spot.

For Decoration - The small, ball-shaped flowers are fragrant and fluffy, and are effective as a filler in a design. Whole branches worked into large designs lend colour and scent to a room. Mimosa is popular for early weddings in the USA, where it is incorporated in buttonholes as well as bouquets.

North American acacia photograph by Jef Poskanzer, used under a creative commons attribution licence

 

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