A soft-wooded shrub to 40 cm high, with cylindrical to angled stems, covered with brown bristles.
It has a largely coastal occurrence in NSW, growing from Yamba on the north coast, with a disjunction to Nabiac-area then with many records in the Sydney area, extending in scattered patches down the coast and ACT into eastern Victoria.
It grows in heath and dry sclerophyll woodland to forest on sand or sandstone.
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, leaves are in whorls of 4 to 6, with other leaves alternate or opposite towards the base; to 10 mm long, and to 2 mm wide, with the upper surfaces have warty-glands.
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, to 25 mm in diameter, lilac-pink in colour, produced throughout the year but mostly July to December.
Tetratheca spp. produce fruit as capsules which open longitudinally.
In this species, they are elliptic to oblong, to 8 mm long, with seeds to 4 mm long, brown in colour, with fine hairs and an appendage.
This species is known to be cultivated (both in Australia and overseas). Check with local nurseries for availability.
An attractive plant in flower that grows at its best on well-drained moist soil with protection from full sun. Can also be grown in a pot.
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.
There is mention online of a cultivar called ‘Heathland Gem’. However, it is not known if this is available in Australia.
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.
ericifolia – From Latin meaning with leaves like species in the genus Erica (Heather or Heaths).
This species is not considered to be at risk of extinction in the wild.
NSW Flora online (PlantNET) Tetratheca ericifolia profile page:
The Family Tremandraceae – APS NSW
Wikipedia profile page for genus Tetratheca (including a list or many of the species):
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.