A low, spreading, prostrate and not overly vigorous groundcover-shrub, with stems up to 60 cm long.
It has a mostly coastal distribution in NSW, stretching almost into the central tablelands and as far south as around Bega. It grows along the coast into Queensland, to around Bundaberg.
It is typically found in dry sclerophyll forest and woodland on gravelly-clay soils, sometimes rocky.
Callistachys is a member of the “pea” family. This generally means that leaves are alternate with stipules at the base of the petioles. Callistachys spp. have simple but usually opposite leaves (or almost opposite), with stipules present which are usually stiff and bristly. Leaves can be entire or with crenulate margins, usually with a pungent point and with conspicuous reticulation on the upper surface, with the lower surface usually hairy. In this species, the leaves are mostly arranged oppositely, oval to egg-shaped to elliptic, to 7 cm long and to 2.5 cm wide; upper surface is dark green, shiny and veined, lower surface is paler with occasional hairs; the apex either sharp, rounded or notched.
Flowers are, of course, pea-shaped (a term sometimes used is papilionate), with 5 petals in a fixed arrangement; the main back petal is called the “standard”, two lateral petals called “wings” and two fused petals at the bottom called the “keel” (in which the anthers and one carpel tend to be hidden).
In Callistachys, flowers are a mixture of red and yellow (or orange/yellow) and are usually arranged singularly or in racemes, clusters or corymbs. The upper two of five sepal lobes are fused higher up, compared to the other 3. There are bracetoles and bracts produced on the flowers but these fall early as flowers develop. The bracts are often 3-lobed, a distinguishing feature of the genus. In this species, flowers are borne in racemes in leaf axils or at the branch terminals, with flowers about 10 mm long, orange or yellow, with brown-reddish markings on the standard which is about 20 mm across; occurring in spring to summer.
The fruit of all peas is a pod. In this species, they are approximately 10 mm long, ovoid to oblong and hairy.
This species is not often cultivated but known to make a good groundcover and can be cultivated successfully.
In a garden situation, it is an excellent, if small, ground cover for a position in full sun or light shade. It will grow in heavy soils provided they are not permanently wet and it tolerates at least moderate frost.
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
The seed retains viability for many years.
Cuttings strike well using firm, current season’s growth.
This species was previously referred to as Podolobium scandens. Three species of Podolobium, including this one, have been recently re-classified into Callistachys – a previously purely Western Australian genus. Further study continues.
This species used to have recognised varieties but these are no longer accepted or referred to.
This species would likely die in a fire and regenerate from the seedbank.
Callistachys is currently a genus of about 5 species, endemic to Australia, occurring in Western Australia, Queensland, New South Wales and Victoria. NSW currently has 3 species.
Callistachys – From the Ancient Greek – Kallos (κάλλος) – meaning “beautiful” (which is changed to κάλλη to describe a noun) and –stachys (σταχυς) meaning a “spike of flowers” – referring to the showy spikes of some species.
scandens – Latin meaning “climbing” (although this plant does not climb strongly).
This species is not considered to be at risk of extinction in the wild.
Australian Native Plants Society Australia profile page – Podolobium scandens
NSW Flora Online (PlantNET) – Callistachys scandens profile page