A clumping lily-herb with basal laves on compressed rhizomes to 10 cm long, with inflorescences to 1.5 metres tall.
It has a large natural occurrence in NSW, growing along the entirety of the coast, tablelands and western slopes subdivisions, as well as, the north-western plains.
It grows further afield from the eastern parts of SA, right through Victoria, the rough eastern half of Queensland, and the far north of NT and WA, as well as Tasmania.
It is generally found in moister areas, such as near creeklines, in dry and wet sclerophyll forest as well as woodlands, grasslands and heathlands.
Dianella spp. produce their leaves on a buried condensed rhizome, with some species exhibiting aerial stems with alternate to clustered leaves.
In this species, the leaves are produced basally in a clump, mid to dark green, softish, linear to subulate (“strappy”) to 80 cm long and to 2.5 cm wide, with a rounded to keeled sheath. The leaf bases are partly occluded (where the two halves of the upper side of the leaf are folded length-wise and glued together). However, the halves are not tightly joined in this species and can be separated by inserting a finger (a useful identification feature).
Dianella spp. produce flowers on elevated inflorescences, usually above the foliage, which are described as cymose but have a panicle-like appearance. The individual flowers are blue to violet and are arranged in branches on the main axis.
In this species, the inflorescences are produced well above the foliage to 1.5 metres tall; flowers can be pale blue to purple, white or greenish, occurring in spring and summer. The stamens have orange filaments and yellow anthers (a useful identification feature).
Dianella spp. produce berries, usually purple in colour.
In this species, berries pale blue, to 7 mm in diameter.
D. longifolia is an attractive drought-tolerant and frost-tolerant plant for the garden, long-lived once established. It prefers a well-drained soil in a sunny or semi-shaded position. D. longifolia is widely used in revegetation work.
A worthy plant for the garden especially planted in odd numbered clumps.
It is a great gap filler and can provide some dense cover for small reptiles and invertebrates.
It may not thrive in overly wet conditions and can tolerate dry periods.
Most plants in this genus are fast growing and hardy once establish in well-drained soils, in a sunny or semi shaded position.
After flowering and after the berries are finished, remove flower spikes at the base of the plant and at the same time remove any dead or yellowing leaves.
Use a suitable native fertiliser for better flower displays.
Propagation can be from the ripe seed sown in spring with good success.
A benefit of Dianella, along with many other monocotyledonous plants, is they can be transplanted. This is best done in Autumn and Winter. Plants can be dug up and divided along the rhizomes and replanted. It is best to cut back the foliage by two-thirds if doing this and replant, where desired, quickly. The author has found this is the quickest way to establish a sizeable plant. Keep transplanted plants moist for a few weeks.
Six varieties of D. longifolia have been described and accepted by the Australian Plant Census:
• Dianella longifolia var. fragrans – found near Cardwell in Queensland
• Dianella longifolia var. grandis that is widespread in south-eastern Australia, from near Gympie to north of Adelaide;
• Dianella longifolia var. longifolia, found throughout northern and eastern Australia, including the Kimberley region of Western Australia;
• Dianella longifolia var. stenophylla in eastern Australia from near Gladstone to near Batemans Bay;
• Dianella longifolia var. stupata found mostly west of the Great Dividing Range in eastern Australia;
• Dianella longifolia var. surculosa that occurs in south-eastern Queensland and north-eastern New South Wales
Two of these varieties are currently recognised in NSW; var. longifolia and var. stenophylla.
There is a cultivar named ‘Forte’ which has narrow leaves and is reported to be hardy.
Dianella is a genus of about forty species of monocotyledonous flowering plants (which have been subject to family reclassifications in recent times). They are commonly known as Flax Lillies and are closely related to other native genera such as Thelionema and Herpolirion, as well as, more broadly to Xanthorrhoea and Lomandra.
The genus has much variation and there are likely more species which require formal descriptions.
To view the list of Dianella species accepted by the World Checklist of Selected Plant Families as at October 2020, use this link.
First Nations Peoples Uses: D. longifolia var. grandis is believed to have medicinal properties. Root extracts have demonstrated antiviral activity. Leaf fibres are used for weaving baskets and for cord; the berries are eaten raw and the roots pounded and cooked on hot rocks.
Most Dianella plants will survive fire; regenerating quickly from rhizomes as well as any seedbank.
Dianella – Latin diminutive of Diana – the Roman Goddess of the hunt and wild animals, often associated with woodlands. The first specimen of this genus was collected from the island of Mauritius by French botanist-explorer Philibert Commerson (1727-1773) and was simply labelled “Diana”.
longifolia – Latin, meaning “long leaved”.
Not considered to be at risk of extinction in the wild.
Greening Australia – Florabank – Dianella longifolia profile page
NSW Flora Online (PlantNET) – Dianella longifolia profile page
Wikipedia – Dianella longifolia 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.