A herbaceous to woody perennial with basal leaves and leafy flowering stems growing to 1 m tall.
It is highly variable (polymorphic) and widespread species occurring in all regions of New South Wales. also in Queensland, Victoria, Tasmania, and South Australia.
It can be found in a wide range of habitats – mainly dry sclerophyll woodlands but also shrublands, mallee country and wet sclerophyll forests, on all soil types.
It is considered a species complex which may have up to 10 or 20 different forms/species. When some populations are compared, it is hard to believe they are the same species.
Ajuga spp. have simple leaves with basal leaves arranged in a basal rosette. The flowering-stem leaves (cauline leaves) are opposite and in pairs.
In this species, 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 ranging right through to glabrous.
The cauline leaves are also highly variable and can be short and somewhat triangular or ovate to lanceolate / oblanceolate with either smooth margins or strong lobing, to 50 mm long by 25 mm wide.
Being in the Lamiaceae family, the flowers are labiate with 5 uneven petals, often described as upper and lower ‘lips’. In this species, they are usually deep blue or purple but pink and white forms are also known. They range from 5 to 25 mm long, somewhat tubular 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 per axil, 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.
This species is cultivated by many native gardeners and plants are sometime seen for sale at native and other nurseries.
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.
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.
It grows well in average sandy to clay 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) where it grows very well.
Forms have also been observed growing at Sylvan Grove Garden, Picnic Point (NSW).
Plants can be dug up and transplanted and some forms produce a colony of vegetative ‘pups’. If transplanting, be sure to dig up a fair bit of root system and give a lot of water for a week or two when moving to a new home. Some forms do not survive in gardens but there are many that do.
No known pests or diseases.
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.
It 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).
First Nations Peoples of Australia, 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 is a genus of about 40 species with a worldwide distribution. They are commonly called ‘Bugles’. There is only this one variable species in Australia and New South Wales.
Ajuga – means “a-jugate”, meaning 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 – Latin – “southern”, referring to the distribution of the species. There are also northern hemisphere Ajuga species.
This species is not considered to be at risk of extinction in the wild. In time, new species will be recognised and some of these may be rare.
NSW Flora Online (PlantNET) – Ajuga australis profile page
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.