Acacia obtusifolia grows to a large-shrub or small tree, to 8 m high.
It is found chiefly in NSW in the coastal subdivisions and into the tablelands, extending to the central western slopes. It grows commonly along the south and central coasts and extends towards Gulgong. There are then disjunct records scattered up the north coast and into Queensland, where it grows as far as potentially the Maryborough area. It extends into the very eastern parts of Victoria.
It is usually found on sandy and sandstone substrates but also on basalt. It grows in wet and dry sclerophyll forest and margins of rainforest, woodland and heath.
Australian Wattles at least, can be broadly placed into 1 of 3 recognisable groups:
This wattle belongs to Group 2.
The phyllodes (modified leaves) are narrowly elliptic to linear, to 20 cm long and 3 cm wide with prominent longitudinal veins and a blunt apex, often with a leathery texture.
The pale-yellow to cream-coloured flowers, are produced in spikes (cylindrical heads) up to 5 cm long, produced singularly or pairs (1s and 2s) in the phyllode axils. Flowering is in summer.
Seed pods are straight, to 15 cm long and 0.5 mm wide.
Currently, not much is known about its cultivation. It is very morphologically similar to Acacia longifolia which is known to grow well in gardens and landscapes, at least for several years.
It likely needs a well-drained soil to do well and a semi-sunny position
Acacias can suffer from a number of pests, including borers, scale, galls and leaf miners. Growing plants suitable to your local environment minimises these occurring.
Propagation is easy from scarified seed by covering with boiling water for 24 hours and discarding any seeds still floating on the surface.
Very morphologically similar to Acacia longifolia, which it can be confused with. The two species flower at different times with A. longifolia flowering in late-winter / spring and A. obtusifolia flowering in summer. A. obtusifolia also has resinous phyllode margins.
Most wattles regenerate from seed after fire with some species exhibiting suckering from the bases.
Acacia is a highly diverse genus, with over 1500 recognised species (placing it in the top-10 most-diverse plant genera) occurring in most continents except for Europe. Australia has about 970 spp., most of which are endemic. There are also about 10 exotic species. NSW has about 235 recognised species. Some species have become weeds in other states outside of their natural range (e.g., wattles from Western Australia into NSW and vice versa).
Acacia – from Greek Akakia – which refers to an Ancient Greek preparation made from one of the many species; the name of which derives from akis, meaning “thorn” – referring to the thorns of species in Africa.
obtusifolia – refers to the blunt (obtuse) tip / apex of the leaf.
This species is not considered at risk of extinction in the wild.
Wattle – Acacias of Australia Online – Acacia obtusifolia profile page https://apps.lucidcentral.org/wattle/text/entities/acacia_obtusifolia.htm
NSW Flora Online (PlantNET) – Acacia obtusifolia profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Acacia~obtusifolia