by Natarsha McPherson

Your Adelaide Park Lands are home to many kinds of plants, but it’s not always easy to identify them.

Continuing this series, Know Your Park Lands Plants, we take a closer look at the plants that call your Park Lands home.

The native scurf pea (Cullen australasicum; Psoralea australasica), or the tall scurf-pea, is a perennial shrub best recognised for its high drought tolerance and vibrant appearance during flowering.

Isolated examples have been spotted:

here, behind the Zoo in Mistletoe Park / Tainmuntilla (Park 11);
here, at the start of the Bunyip Trail in John E. Brown Park (Park 27A);
here, in Bonython Park / Tulya Wadli (Park 27);
here, near the motor racing circuit, and
also here a hundred metres further south in Victoria Park / Pakapakanthi (Park 16)

Outside of your Park Lands and the city, the species is native to Australia’s arid zones, with high concentrations observed in regions with low annual rainfall, dry creek lines, rocky gorges, and land depressions.

Across this distribution, the herbaceous shrub grows up to 2.5m in height and 1.5m in width.

*The native scurf pea in Victoria Park / Pakapakanthi (Park 16) Photo: Dr Manfred Jusaitis/iNaturalist.*

Leaves of the species are trifoliate – arranged in groups of three toothed, ovate leaflets that form structures measuring approximately 12cm in length.

Individually, each leaflet generally grows between 1-5cm long and 1-3cm wide, with colour and texture varying from light to dark green and smooth to sparsely hairy.

However, a better indicator for identification is the shrub’s vibrant flowers. Inflorescences (flower heads) typically comprise flowers arranged in groups of three, which are situated at regular intervals along flower-bearing stems.

These flowers, although small (5-8mm), can often be spotted all year round, with their colours ranging from light pink to dark violet.

Less obvious, however, are the shrub’s black seed pods, which are obliquely egg-shaped and measure only around 4mm long and 1.5mm wide.

Within each pod is a single light-brown, haired, kidney-shaped seed that demonstrates no unique dispersal mechanism, relying on a combination of strategies (e.g. wind, water, animals) for effective establishment.

*Photo: South Australian Seed Conservation Centre.*

Although the native scurf pea is largely drought-tolerant and yields a high quantity of seeds per plant, its distribution and establishment is affected by frost sensitivity and grazing.

Often concentrated in arid pastoral regions, the species is a palatable and nutritional food source for a variety of fauna, including sheep, cattle, kangaroos, and birds such as parrots and galahs.

However, within your Adelaide Park Lands, you’ll find that its role is more central to the life cycle of butterflies.

In particular, the herbaceous components of the shrub are an important larval food source for species like the Chequered Swallowtail (Papilio demoleus).

*A Chequered Swallowtail butterfly on a native scurf pea.* *Photo: Chloe Johnson/Wikimedia.*

If you’d like to know more about the plants in your Park Lands, head over to iNaturalist, where you can record, share, and discuss your findings with fellow naturalists.

There is an iNaturalist page that can show you exactly where citizen scientists (like you!) have observed the native/tall scurf pea.

See the other plants featured in this series here.

Banner image, top, by Emilie Vallez/iNaturalist.