Harknessia globosa is somewhat of a mystery. It was first described in 1971 from a collection made in Taranaki in 1922 from a tree recorded as Eucalyptus globulus. As far as is known this was the only record until the fungus was rediscovered on totara in 1976; H. globosa is thus unlikely to be native to New Zealand. Further research has revealed that H. globosa is prevalent on both totara and Hall’s totara in the central North Island and in Hawke’s Bay, and in both regions appears to be strongly associated with bud and shoot deaths — on some trees as much as 3 0 - 40% of the annual seasonal growth has been killed. However, the results of laboratory tests on the pathogenicity of this fungus, and of the Seiridium sp., have proved inconclusive.

Type: Foliicolous Fungi; Description: Conidiomata pycnidial, scattered to gregarious, subepidermal, immersed becoming partly erumpent, globose to depressed globose, dark brown, 0.3–0.4 mm in diameter, opening by an irregular fissure; predominantly on lower surfaces of leaves, occasionally on both sides. Conidia globose to subglobose, 0-septate, 14–18 × 11–14 μm, smooth, brown; basal appendage cylindrical, flexuous, 4–10 × 2 μm, smooth, hyaline.

Distribution: Northland, Auckland, Bay of Plenty, Taranaki, Taupo, Gisborne, Hawkes Bay, Wairarapa, Nelson, Marlborough Sounds, Mackenzie.; 1st Record: Sutton (1971).

Significance: Of no significance on eucalypts. Recorded as strongly associated with bud and shoot death in Podocarpus hallii and P. totara in central North Island and Hawkes Bay (Anonymous 1982).; Host(s): Eucalyptus cinerea, E. globulus subsp. globulus, E. microcorys, Podocarpus hallii, P. totara.

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

SPECIMEN EXAMINED Harknessia globosa folder in Herb. IMI. On Eucalyptus globulus, Taranaki, New Zealand, x. 1922, W. Smith, type of H. globosa (21815).

Fructifications abundant, amphigenous, separate, immersed, subepidermal, globose to subglobose, unilocular, erumpent and punctate, 300-400 µ diam.; basal and lateral walls of the stroma evenly 4-8 cells thick, of subhyaline to pale brown, thin-walled pseudoparenchyma, becoming hyaline towards the conidiogenous region; no definite ostiole is present but the pale brown pseudoparenchyma is of a loose texture in the apical region of dehiscence and forms the furfuraceous border. Conidiogenous cells formed from the inner cells of the stroma wall, long lageniform, 4-6µ wide at the base and 1-septate approximately 5-7~t from the base, 2.5-3.5~t wide towards the apex, hyaline, smooth. walled, unbranched 16-29 µ, long. Conidia holoblastic, aseptate, globose to subglobose, dark brown, with a large, central, globose to irregular guttule, smooth-walled, 14-16 (14.5) x 12-13.5 (12.5) µ, with the conidiogenous cell persisting as a cylindrical, hyaline, basal appendage devoid of cytoplasm, 2-7 µ long.

Fructificationes abundantes, amphigenae, discretae, immersae, subepidermales, globosae vel subglobosae, uniloculares, erumpentes et punctatae, 300-400µ diam.; omnes massae nigrae conidiorum semper circumcinctae margine distincto furfuraceo; parietes basales et laterales stromatum 4-8 cellulis crassis, ex cellulis subhyalinis vel pallide brunneis pseudoparenchymaticis compositi, qui suet hyalinis versus partem cellulorum conidiogenorum; ostioli distincti absentes, sed pseudoparenchyma pallide brunneum texturis incohaerentibus marginem furfuraceum facit. Cellulae conidiogenae ex cellulis interioribus parietis stromatibus formatae, longae lageniformiae, ad bases 4-6µ latae et interdum 1-septatae, versus apices 2.5-3.5 µ, latae, hyalinae, laeves, non ramosae, 16-29 µ, longae. Conidia (blastosporae) aseptata, globosa vel subglobosa, laevia, atro brunnea, 14-16 (14.5) x 12-13.5 (12.5) µ, cum guttula centrali globosa vel irregulari et appendice hyalina nonramosa basali ex conidiophoro persistenti oriunda, 2-7 µ longa.

In foliis emortuis Eucalypti globuli, Taranaki, New Zealand, 2 Oct. 1922, W. Smith, typus (21815).