Common Name

Northern Steedman’s Wattle, Roadside Wattle (in the Pilbara)

Family

Fabaceae

Distribution

Occurs in central Hamersley Ra. and to the E where it is scattered though the Little Sandy Desert to the Rudall River Natl Park and near the Carnarvon Ra., W.A.

Description

Obconic, multi-stemmed shrub or tree. Phyllodes mostly 5–8 cm long and 8–15 mm wide. Racemes 1–4 cm long; peduncles 2–4 mm long; heads 40–50-flowered. Pods to 12 cm long, 5–6 (–10) mm wide. Seeds 4.5–6 mm long; funicle completely encircling the seed in a single or double fold (expanded length 30–40 mm long).

Habitat

Grows in red sand on sandplains, on rocky scree slopes and around the edges of steep breakaways and cliffs. It is best developed (sometimes forming thickets) along floodplains, drainage lines and in water-gaining sites; common along road verges in many places.

Specimens

W.A.: upper Rudall R. area near Curran Curran Rockhole, B.R.Maslin 2139 (CANB, G, K, MEL, NY, PERTH); between Marandoo and Hancock Gorge, N of Mt Bruce, B.R.Maslin 4675 (CANB, PERTH); Little Sandy Desert, A.S.Mitchell 514 (NT, PERTH).

Notes

An entity of uncertain taxonomic status, but with affinities to subsp. borealis, occurs in the Little Sandy Desert. It is characterized by having a wispy growth form and atypically long phyllodes (14–18.5 cm) and was included by B.R.Maslin in J.Jessop (ed.), Fl. Central Australia 133 (1981), as A. aff. validinervia and noted by B.R.Maslin, Fl. Australia 11A: 279 (2001) under A. validinervia. This entity is currently known under the phrase name Acacia sp. Lake Disappointment (S.van Leeuwen 2865).

Subspecies borealis can resprout from a basal woody rootstock following fire. It probably has a relatively fast growth rate and regenerates from seed. These attractive plants have white stems and showy, fragrant, golden heads, and as such would be well-suited for amenity plantings and in home gardens in arid areas.

Although this subspecies was treated as A. steedmanii by B.R.Maslin in J.Jessop (ed.), Fl. Central Australia 132 (1981) it was included within the circumscription of A. validinervia by B.R.Maslin, Fl. Australia 11A: 279 (2001).

A specimen from the Rudall R. area (B.R.Maslin 2139) with atypically wide pods (8–10 mm) is noted by B.R.Maslin, Fl. Australia 11A: 279 (2001), where A.S.George 10839 was erroneously cited as the voucher, see B.R.Maslin, Nuytsia 18: 169 (2008) for discussion.

FOA Reference

Flora of Australia Project

Author

B.R.Maslin