(Cunningham, 1923b) Cunningham (1931a) stated that both host and rust are introduced from Australia; the former is grown as a shade tree in warmer parts of New Zealand. The rust has been collected only on leaves of Acacia melanoxylon from Te Kauwhata in the Auckland Province.

Type: Rust and Smut Fungi; Description: Spermagonia numerous, aggregated, erumpent, light rust-coloured, powdery, minute, up to 0.8 mm in diameter, on small galls; on both sides of juvenile leaves, phyllodes, and petioles, and on depressed cankers up to 4 mm long on twigs and small branches. Uredinia pustular, together with the telia partially surrounding the spermagonia in circular or elliptical groups up to 4 mm in diameter. Urediniospores intermixed with the teliospores, elliptical, 34–48 × 16–22 μm, pallid yellow chestnut brown, densely verrucose. Telia pustular, together with the uredinia partially surrounding the spermagonia in circular or elliptical groups up to 4 mm in diameter. Teliospores intermixed with the urediniospores, solitary on sporophores, which have a lateral vesicle; teliospores depressed globose to globose, 19–26 × 25–34 μm, dark chestnut brown, smooth; vesicle globose or obovate, 25 × 20 μm, hyaline.

Distribution: Auckland, Coromandel, Waikato, Bay of Plenty, Taranaki, Taupo, Rangitikei, Wanganui, Wellington, Gisborne, Hawkes Bay, Wairarapa, Nelson, Buller, Westland, Mid Canterbury.; 1st Record: Cunningham (1923a).

Significance: Generally of minor importance. When infection is severe, cankers may girdle twigs and branches, causing dieback of parts of the crown.; Host(s): Acacia melanoxylon.