Gastrolobium grandiflorum, commonly known as Wallflower Poison, Wallflower Poison Bush or Heart-leaf Poison Bush, is a bushy shrub which is endemic

Endemic (ecology)

Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...

 to Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

.

It grows to 2 or 3 metres in height and between late summer and early winter (February to August in Australia) it produces orange-red pea-flowers with a yellow centre and red veins. The leaves

Leaf shape

In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...

 are hairy and heart-shaped on younger plants and elliptic and more glabrous on older plants, up to 6 cm long and 2.7 cm wide.

The species was first formally described by botanist Ferdinand von Mueller

Ferdinand von Mueller

Baron Sir Ferdinand Jacob Heinrich von Mueller, KCMG was a German-Australian physician, geographer, and most notably, a botanist.-Early life:...

 and published in Fragmenta Phytographiae Australiae in 1863. It is the most widespread within the genus, occurring across a large area of Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

 , as well as in the Northern Territory

Northern Territory

The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...

, Western Australia

Western Australia

Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

 and South Australia

South Australia

South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

.

Poisonous attributes

The species, like many others within the genus Gastrolobium

Gastrolobium

Gastrolobium is a genus of flowering plants in the family Fabaceae. There are over 100 species in this genus, and all but two are native to the south west region of Western Australia....

, contains high levels of monofluroacetic acid (the active ingredient in the pest control toxin known as 1080) The leaves, seeds and roots are highly poisonous to cattle, sheep, horses and goats. Major livestock losses have been attributed to the plant in Queensland.

In 1896, the explorer and gold prospector David Carnegie came across the plant in Western Australia on the return leg of an expedition from Coolgardie

Coolgardie, Western Australia

Coolgardie is a small town in the Australian state of Western Australia, east of the state capital, Perth. It has a population of approximately 800 people....

 to Halls Creek

Halls Creek, Western Australia

Halls Creek is a small town situated in the East Kimberley region of Western Australia. It is located between the towns of Fitzroy Crossing and Turkey Creek on the Great Northern Highway...

 later writing:

All along the banks of the creek splendid green acacia and grass was growing, and a most inviting-looking plant standing some six feet high, with greenish-grey stems and leaves, and a flower not unlike wallflower

Wallflower

Erysimum is a genus that includes about 180 species, both popular garden plants and many wild forms. The genus Cheiranthus is sometimes included herein whole or in part. Erysimum has recently adscribed to a monogeneric cruciferous tribe, Erysimeae...

. Such a place at once suggested camping, and we were proceeding to unload when Godfrey remarked that this pretty plant was very like a most deadly Queensland poison plant; he was not sure; I had never seen it before, nor had Breaden. The risk, however, was too great; it might be poison; I could see the camels eyeing its fresh charms, and it grew in such profusion that all would be devouring it in a few minutes. So we packed up again and moved further on, much to the disgust of the blacks and the animals, for all were very tired. I collected some specimens of this plant; if Godfrey had never been in Queensland we should have been in a tight corner.

So toxic is the plant to farmed animals that, following bushfires, cattlemen in north-western Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

have to move livestock before the heart-leaf emerges from the ashes.