A highly variable widespread species occurring in all regions of New South Wales, also in Queensland, Victoria, Tasmania, and South Australia. It can be found in a range of soils and habitats from coastal forests to the dry, mallee country.
It is considered a species complex which may have up to 10 or 20 different forms/species.
It is a soft-wooded herbaceous plant, growing to 1 m tall and about 50 cm wide.
Has a basal rosette of leaves from which flowering (cauline) stems arise.
Basal leaves are variable and can be lanceolate, obovate or elliptic, to 15 cm long 4 cm wide. They can be green, grey-green, or blue-grey with very strong purple undersides in some plants. Leaves can be densely hairy or glabrous.
The flowering stems have pairs of opposite leaves. These are also highly variable and can be short and somewhat triangular or ovate to lanceolate / oblanceolate with either smooth margins or strong lobing.
The flowers are usually deep blue or purple but pink and white forms are also known. They range from 5 to 25 mm long, somewhat tubular (labiate) in shape with a short upper lip and a long, spreading lower lip. Flowers are produced in the leaf axils in more or less a ring around the stem, with flowers few or many.
Flowers are seen mainly in spring and summer. Flowering stems can be erect, decumbent or prostrate.
Each flower produces a cluster of 4 woody nutlets (mericarps) about 3 to 5 mm long.
The plants live for around two to three years in the wild.
Although not widely cultivated, A. australis is a useful small plant which deserves to be better known. Plants prefer semi shade but tolerate full sun and extended dry periods once established. It is also tolerant of at least moderate frosts. It will succeed in a range of soils except those which are poorly drained.
It is well worth the effort sourcing this plant for its blue coloration.
Dan Clarke (editor)’s note: This editor studied this plant as a Honours year project and discerned several distinct forms across NSW. It is likely that the plant could be more popular in cultivation if it was promoted over exotic forms.
Grows well in average sandy garden soil, although some forms do better than others. A form from Mt Panorama, Bathurst was established at Joseph Banks Native Plant Reserve, Kareela (NSW).
Forms have also been observed growing at Sylvan Grove Garden, Picnic Point (NSW).
Propagation is easy from cuttings which usually strike reliably and quickly. Propagation can also be carried out from seed.
Plants can also be transplanted with good success, from a process of separating “pups” from adult plants at the basal areas. This works best if the site soil is also used for transplanting.
This species is likely to be recognised as several species in the future.
Likely regenerates from seed after fire. May reshoot from basal areas. Plants at some populations have been observed to be connected underground (lateral suckering/layering).
Aboriginal people in some areas used this plant as a bush medicine. They would bruise and soak the leaves in hot water to make an infusion to bathe sores and boils.
Ajuga – means a-jugate, not joined or yoked from the Latin jugatus. In this genus, the sepals are free and are seen as 5 separate teeth or lobes. In some other Lamicaeae genera (such as Prostanthera) the sepals are joined into two lips.
australis – southern, referring to the distribution of the species. There are also northern hemisphere Ajuga species.
Not considered to be at risk in the wild.