Hypophylla. Maculis nullis. Soris subrotundatis, subgregariis, mox apertis, pulverulentibus, aureo-fuscis (1 m.m. diam.). Uredosporis globoso-ovatis, laevibus, pallido flavidis (22 x 15 µ), breviter pedicellatis.

On living leaves of Olearia Lyallii. Port Ross, New Zealand. (Kirk, 374.)

Host: Olearia Lyallii Hook. f. On leaves. Herb. No. 42. Port Ross (Auckland Islands), T. Kirk! 1890. (Type collection.)

II. Uredosori hypophyllous, seated on discoloured spots visible on the upper surface, orbicular; 1 mm. diam., pulverulent, reddish-brown, deeply seated in the dense tomentum clothing the leaf-surface. Spores subglobose, elliptical, or obovate. 42-55 X 35-40 mmm.; epispore hyaline, coarsely and sparsely echinulate, varying in thickness from 3 to 6 mmm., cell-contents granular, tinted ferruginous; germ-pores indistinct.

Distribution : Auckland Islands.

The host is endemic, and is confined to the Auckland Islands and the Snares. (Cheeseman, 1906, p. 283.)
The published description of Cooke's is far from accurate; as the spores are stated to be 22 X 15 mmm., and the epispore to be smooth. Fortunately I have part of the type collection, and the above description has been drawn up from this. The epispore in different spores varies in thickness, and when mounted and examined in the usual manner is seen to be very irregular; when the spores are boiled for a few seconds in lactic acid the outer covering swells somewhat and a distinct inner wall becomes visible (fig. 125, a). The large size of the spores, together with the thick coarsely-echinulate epispore, serve to characterize the species.

Type: Rust and Smut Fungi; Description: Uredinia rounded, reddish brown, up to 1 mm in diameter; deeply immersed in tomentum on the lower surfaces of leaves in discoloured spots, which are visible on the upper surface. Urediniospores obovate to elliptical, 42–55 × 30–40 μm, coarsely and sparsely echinulate, hyaline.

Distribution: Stewart Island, Auckland Islands.; 1st Record: Cooke (1890b).

Significance: None.; Host(s): Olearia lyallii.

[Notes from Kew Type specimen, PRJ 2010] Kew images.

Auckland Islands (Cooke 1890;Cunningham 1924, 1931; Sydow and Sydow 1924; McKenzieand Foggo 1989), Port Ross, coast, on Olearia lyallii Hook.f. [Asteraceae], 1890, T. Kirk (PDD 42 – II – isotype); on O. lyallii, November 1907, B.C. Aston (PDD 10076 – II);Ewing Island, on O. lyalli, December 27, 1962, F.J. Fisher(PDD 40284 – II ex CHR 134024); on O. lyallii, February13, 1987, W.R. Sykes (PDD 52963 – II); Port Ross, near Hardwicke site, on O. lyallii, March 22, 2000, E.H.C. McKenzie (PDD 87910 – II); Enderby Island, on O. lyallii, March21, 2000, E.H.C. McKenzie (PDD 87911 – II).

This endemic rust is known only from the Auckland Islands and Stewart Island. Wilson (1982) stated that Olearia lyallii was introduced from Snares Islands to Auckland Islands, and that it is very similar to the coastal leatherwood (O. colensoi Hook. f.) of Stewart Island.