A soft-wooded shrub to 30 cm high.
It occurs naturally in the general south-eastern quarter of NSW, mainly on the tablelands and western slopes, growing south from around Dubbo, through areas such as Orange-Bathurst, west of Lake Burragorang, the Southern Highlands and then further south through the ACT (where most of its occurrence is), extending south-east to the west of Melbourne. It extends as far east as around Braidwood in NSW, moving closer to the coast on the NSW/Victorian border.
It typically grows in exposed rocky areas in dry sclerophyll woodland and forest.
The stems have a wiry structure, either cylindrical or 4-angled, with hairs.
In Tetratheca spp., leaves are simple and can be arranged alternately or in opposite pairs or whorls. Some species can exhibit varying leaf arrangements (dimorphic). In this species, the leaves are in whorls of 4 to 6, to 10 mm long and to 4 mm wide, narrow-elliptic to obovate with incurved tips.
Tetratheca spp. tend to produce solitary or paired flowers in leaf axils, well beyond the foliage. They typically have 4 petals which resemble an even cross (some flowers can have 5 petals), with 8 stamens and 1 carpel. Flowers often point downwards (pendent) which attracts certain insects. In this species, flowers are solitary or occasionally paired, deep-lilac to pink or mauve in colour (rarely white); to 20 mm in diameter; in September–December.
Tetratheca spp. produce fruit as capsules which open longitudinally. In this species, the capsules are to 8 mm long, with seeds to 4 mm long, brown in colour with an appendage.
This species is reported to be able to be cultivated if plants can be sourced (although not much information is currently available online re cultivation).
It is an attractive small plant with its perfumed pink bells along the stems. It is suitable for a shady garden, preferring morning sun only in moist well drained soils.
Some Tetratheca spp. are cultivated commonly, especially T. thymifolia and they make very attractive additions to gardens.
Plant them along open borders or in rockeries for best affect, with well-drained soils and some shade during the warmer months.
Propagation can be carried out from seed but this is rarely available.
Cuttings of hardened, current season’s growth usually strike fairly-readily. Cuttings of young suckering shoots will also work well provided the propagation mix is well-drained. The use of a root-promoting hormone is advised for greater success. Cuttings are best done from November to April.
Tetratheca comprises around 50 to 60 species, endemic to Australia. They occur in all states with the exception of the Northern Territory. NSW currently has 16 species.
The flower colours have given rise to the common name for many species of “Black-eyed Susan”. However, note that this common name applies to several exotic species.
Most Tetratheca spp. would die in a fire and regenerate from the seed bank.
Tetratheca – Ancient Greek – tetra meaning “four”, and theke meaning “sac or box”, relating to the condition of the stamens in the flowers which have four lobes or cells.
bauerifolia – named for its leaves resembling those of species in the native genus Bauera.
This species is not considered to be at risk of extinction in the wild.
NSW Flora online (PlantNET) Tetratheca bauerifolia profile page: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Tetratheca~bauerifolia
The Family Tremandraceae – Australian Plants Society NSW (John Knight) https://austplants.com.au/resources/Documents/South-East-Documents/Articles_About_Plants_and_Gardens/The_Family_Tremandraceae_John_Knight.pdf
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Wikipedia – Tetratheca profile page https://en.wikipedia.org/wiki/Tetratheca