Host: Olearia arborescens (Forst. f.) Ckn. et Laing. Mt. Egmont, Taranaki, 1,000 m., 2/23. E. H. Atkinson!; 1,300 m., 4/25, J. C. Neill!; 11/27, 1,000 m., G.H.C. Arthur's Pass, Canterbury, 900 m., 1/28. G.H.C. Alecs' Knob, Franz Josef Glacier, Westland, 1,300 m., 1/28 G.H.C.

0. Pycnia chiefly epiphyllous; flask-shaped, sparse, scattered, immersed, associated with the aecidia.
I. Aecidia amphigenous and on petioles and stems, in scattered groups of 3-5, seated on discoloured spots visible on both surfaces, pallid orange, becoming lemon yellow; peridia 0.4-0.5 mm. diam., up to 2 mm. above the leaf surface, at first cylindrical, and scarcely revolute, eroded, becoming lacerate with age; cells polyhedral, to 70 mmm. long, hyaline, thick walled, sculptured. Spores elliptical, or obovate, 38-52 x 22-28 mmm. ; epispore hyaline, 1.5 mmm. thick, densely covered with angular deciduous warts, appearing reticulate.

The host is endemic and common throughout (Cheesem. 1925, p. 919). The aecidium shows a general resemblance to that of Puccimia novae-zelandiae G. H. Cunn. (and was included under this species in a previous paper) in its cylindrical shape, but differs in the hyaline, not tinted epispore, and in this structure being reticulate and not verruculose.

Both host and rust are endemic. This rust is limited in its distribution to subalpine areas in both North and South Islands. Cunningham (1931 a) separated it from aecidial stages of other rusts recorded on Olearia by its hyaline reticulate spores.

Type: Rust and Smut Fungi; Description: Aecia in scattered groups, erumpent, orange to yellow, with a torn margin, up to 0.5 mm in diameter; on both surfaces of leaves, and on petioles and stems, discoloured leaf spots visible on both sides of the leaf. Aeciospores elliptical to obovate, 38–52 × 22–30 μm, covered with angular warts, appearing reticulate.

Distribution: Taupo, Taranaki, Wellington, Buller, Westland, Mackenzie, Stewart Island.; 1st Record: Cunningham (1924b: as Puccinia novae-zelandiae).

Significance: The rust causes little damage.; Host(s): Olearia arborescens.