Gastrolobium calycinum

Distribution Map
Family: Fabaceae subfamily Faboideae
Distribution: Woodland on clay, loam or sandy soils in south Western Australia.
Common Name: York Road poison
Derivation of Name: Gastrolobium...from Greek gastros, stomach and lobus, a pod, referring to the swollen seed pods
calycinum.... From Greek, calyx, a calyx and the suffix -inus, resembling or owning (ie. having a notable calyx).
Conservation Status: Not considered to be at risk in the wild.

General Description:

The genus Gastrolobium consists of over 100 species*, all but two of which are found only in Western Australia. Recent botanical revision has seen all members of the genus Brachysema transferred to Gastrolobium. They are generally small shrubs ranging from prostrate in habit to about 2 metres. Many species of Gastrolobium are known to be poisonous and some have been associated with stock poisoning. Because of this, few gastrolobiums are cultivated, the exceptions being a number of species previously in Brachysema.

Gastrolobium calycinum
Gastrolobium calycinum
Photo: M D Crisp - Australian National Botanic Gardens

Gastrolobium calycinum is an erect or bushy shrub to 1.5 m high. Leaves are variable and are narrow to broadly lance-shaped to about 50 mm long. The pea-type flowers are yellow with a red or pink centre. Flowering occurs in late spring to early summer.

Pea flower diagram   

This species is known to be highly toxic and has been implicated in stock poisoning.

The typical "pea" flowers consist of 4 petals; the "standard", the "keel" and two "wings", as shown in the diagram.

As one of the toxic species, G. calycinum is not usually cultivated. It is, however, an attractive shrub and would probably grow well in well drained soils in full sun to semi-shade.

Propagation is easy from seed following pre-treatment to break the physical dormancy provided by the impervious seed coat. Pre-treatment can be carried out by abrasion or by the use of boiling water (further details can be found in the Seed Propagation page). The seed retains viability for many years. Cuttings strike well using firm, current season's growth.

* Chandler G T, Crisp M D, Cayzer L W and Bayer R J (2002), Monograph of Gastrolobium (Fabaceae: Mirbelieae). Australian Systematic Botany 15 (619-739).

◄◄ Photo Gallery Index    ◄ Photo Gallery Thumbnails    Top ▲
◄ Australian Pea Flowers Thumbnails