The representatives of the Jacksonia genus of Australian native plants often have very distinctive odours so much so that some species are called ‘stinkwoods’. The genus is part of the pea-flower subfamily of the legume family Fabaceae. There are some 40 species in the genus, all of them endemic to Australia. Surprisingly, there are no species endemic to South Australia. Generally the blooms are orange or yellow though they may sometimes be red.
Jacksonias may be found in a variety of habitats from coastal heaths to sclerophyll forests. They are adaptable to a range of soils. A characteristic of the genus is the general lack of leaves on mature plants. The leaves are reduced to small, brownish spines or scales and the green or grey-green stems carry out the photosynthesis necessary for the plant to survive.
Jacksonia furcellata is commonly known as grey stinkwood. It is very common on the Swan Coastal Plain of Western Australia and is a leafless shrub or small tree which is broom-like in its appearance. It often appears on newly cleared land or where the earth has recently been disturbed such as on the verges of new roads. It grows on sandplain country, on rises, swampy depressions and river banks. It varies from a prostrate form to a weeping, erect shrub. The flowering season is from October to March and blossoms of yellow, orange and red appear. It likes sandy soils.
Jacksonia sternbergiana is also known as green stinkwood or just ‘stinkwood’. The wood when cut has a very distinctive odour. It is found from just north of Perth on the west coast to the southern coast of Western Australia. The leaves are small scales. It has drooping stem-tips and yellow to orange-brown pea-flowers. The pods are hairy.
Jacksonia scoparia is endemic to Queensland and New South Wales. Its common name is Australian dogwood. It is a tall shrub growing to 5 metres and has an upright habit with narrow, greyish foliage (sometimes pendulous) and hard grey bark. It suckers from the roots and is often found growing in areas where drainage is poor. The mature leaves appear as small brown scales.
Profuse clusters of orange to yellow (with a patch of red) flowers are produced from September to November. The pea-flowers are strongly fragrant. Following flowering, small hairy pods appear which are from 6 to 12mm long.
Several of the Jacksonia species are listed are endangered or threatened. J.velveta or Collie jacksonia is one of these as is J.pungens.
This is an eye-catching shrub when in flower. It prefers a warm, well-drained position, will cope with a protected position in seaside gardens and is not susceptible to frosts.
With such varied habits as these plants have, so too do their needs under cultivation vary. Some will not tolerate having the roots sitting in water, some will not cope well with high humidity in summer but there is always a variety suitable to whatever region you live in. Your garden centre representative will be able to advise you as to the best species for your district.