Kingdom: Plantae
Phylum: Chlorophyta
Class: Incertae sedis
Subclass: Incertae sedis
Order: Trentepohliales
Family: Trentepohliaceae
Genus: Cephaleuros
Species: C. virescens
Binomial name: Cephaleuros lagerheimii
Common name: Mahoe leafspot
Below is a description of Cephaleuros lagerheimii published in a recent book by Gadgil, P. D. (in association with Dick, M. A.; Hood, I. A.; Pennycook, S. R.) (2005). Fungi on trees and shrubs in New Zealand. Fungi of New Zealand. Nga Harore o Aotearoa 4: xi + 437 p. Hong Kong: Fungal Diversity http://nzfungi.landcareresearch.co.nz/html/data_descriptions.asp?ID=81-XJD-43&NAMEPKey=1207
Description: Type: Mycorrhizal Fungi; Description: Thallus polystromatic, subcuticular, roughly circular, greyish white (resembling a powdery mildew) finally becoming greenish orange, composed of irregularly branched and interwoven prostrate filaments; on the upper surfaces of leaves. Erect hairs penetrating through the cuticle, cylindrical, with a bulbous base, reddish brown to orange, 20–130 µm long. Sporangiophores erect, 2–many-celled, developing from the prostrate thallus. Sporangia (1–5) borne slightly obliquely on a short curved stalk, produced from the swollen tip of the sporangiophore, globose to slightly elliptical, 22–43 × 17–26 µm, surface roughened. Zoospores biflagellate. Gametangia not known. Leaf spots roughly circular and wide spreading, greyish white with a pale yellow halo on the upper surface, pale yellow on the lower surface.
Distribution: Very common on Melicytus spp. in northern North Island but causes no damage.;
Host(s): Melicytus macrophyllus, M. ramiflorus.
Photo showing the threadlike filaments called hyphae.
Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/