Westringia longifolia is an open, upright shrub that reaches a height of 3 metres by 1.5 metres.
It has a patchy natural distribution in NSW, growing from north of Mittagong through the west of the Greater Sydney area (it is common around Picton and Campbelltown area – near the upper Georges River); then found in the Blue Mountains sporadically and areas such as Wollemi National Park. There is a single record from out near Peak Hill. There is then a disjunction to the northern tablelands subdivision where it extends into Queensland, growing to as far north as the Toowoomba-Caboolture area.
It is found in dry sclerophyll woodland and forests, often on rocky ground and steep terrain above and along river gorges, with soils sandy to alluvial.
Westringia spp. have simple and opposite or whorled leaves, usually in whorls of 3 to 5. In this species, they are in whorls of 3, linear, to 35 mm long and to 2 mm wide; non-aromatic, mid to dark green on both sides, with sparse hairs.
Flowers have a shape described as labiate (applies to all Lamiaceae flowers) with 5 petals varying in their size, fused at their base, produced in leaf axils. One of the identification features which separates Westringia from Prostanthera is that the 5 calyx parts (basal whorl of the flower) are separated into 5 parts, whereas they are fused into 2 ‘lips’ in Prostanthera. Flowers are typically solitary but clustered heavily in leaf axils, appearing as leafy racemes. In this species, the singular flowers are mostly white although there is a form with pale blue-mauve flowers, which can make for a much more attractive plant when in flower. Flowers are about 1 cm long by 1 cm wide and have purple to brown dots in the centre. The flowers are borne prolifically in late winter to early summer (in Sydney), and spring in cooler climates.
The fruit of Westringia are small mericarps or ‘nutlets’. A cluster of 4 is produced at the base of each flower after pollination. They are only 1 to 2 mm long.
Westringia longifolia is one of the best white-flowered native shrubs and could be grown in the foreground of garden beds.
Westringia longifolia grows and flowers best in full sun and well-drained soil. They grow well in dappled light but are not as prolific in flower. They are also a good hedge plant as they will take some pruning, but not too severe as they do not always shoot from old wood.
This is another westringia that can be used for formal hedging to a large degree.
While the flowers do not attract birds they are attractive to native bees.
I have found these are a slender shrub that is quick growing, tough, long living (around 20 years in my garden in Sydney), drought tolerant and a little frost hardy.
Westringia spp. are propagated very easily from cuttings. Seed can also be used.
Several cultivars are available. One is called ‘Snow Flurry’ with white flowers.
Westringia longifolia was first grown in England in the early 1820’s.
For those interested in botanical art, a hand color print of Westringia longifolia appeared in the 1820s London publication, “The Botanical Cabinet” which was a large paper edition of 2000 coloured plates of rare plants introduced into its hothouses and gardens from around the world by Conrad Loddiges (1786–1846). The Loddiges family managed one of the most notable of the eighteenth and nineteenth-century plant and seed nurseries in the village of Hackney, north of London that traded in and introduced exotic plants, trees, shrubs, ferns, palms and orchids into European gardens.
There are about 25 species of Westringia, endemic to Australia, occurring in all states and territories except the Northern Territory. NSW currently has 15 species. There are many cultivars.
Most Westringia spp. regenerate from seed after fire. They can possibly sucker from basal stem-root zones.
Westringia – named after Johan Peter Westring (1753-1833), an 18th century Swedish physician who administered to the King of Sweden and was a botanical authority on lichens.
longifolia – Latin – meaning ‘long-leaved’, in comparison to other species.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Westringia longifolia profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Westringia~longifolia
Gardening with Angus – Westringia longifolia ‘Snow Flurry’ profile page https://www.gardeningwithangus.com.au/westringia-longifolia-snow-flurry-coastal-rosemary/
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.