Cordyceps robertsii Hook. Auckland: Huia, June 1949, J.M.D. (10938). Taranaki: Mt. Egmont, November 1927, G.H.Cunningham (10939). Cordyceps hauturu Dingley. Auckland: W.Cottier (10677).

Stroma byssoid, superficial, forming irregular areas up to 5 mm. diameter on fertile parts of stroma of host; hyphae thin-walled, hyaline 1-2 µ thick. Perithecia superficial, caespitose, in groups of two to five, obpyriform or ovate, 0.3-0.4 x 0.5-0.65 mm., honey coloured, translucent, ostiole papillated; perithecial wall 40-50 µ thick, pseudoparenchymatous, cells 5-10 µ diameter, hyaline thin-walled. Asci cylindrical, linear 200-350 x 4-5.5 µ, tapering to a globose hyaline cap, 2-3 µ diameter, divided by filamentous longitudinal canal, eight-spored, spores loosely twisted into fascicle within ascus. Spores linear, acicular, 180-250 x 1-1.5 µ, multiseptate, dividing into part-spores within the ascus, part-spores almost cuboid 1.5-3 x 1-1.5 µ, hyaline.
Conidial stage: Conidia, sub-globose, 2 µ diameter, hyaline, budding off from tips of pyriform phialides, arranged in fascicles among the superficial mycelium. Isaria sp.

DISTRIBUTION. New Zealand.

>HABITAT. On Cordyceps sp.

Petch (1923) described Byssostilbe tomentosa on Cordyceps dipterigena Berk. and Br. When he discussed this species he stated that this genus is identical with Torrubiella except for the spores which are cuboid and become rounded when mature. He noted that in B. tomentosa the rounded part-spores have not been seen. This species appears to be similar to Torrubiella cordyceps. Lloyd (1917) named and inadequately described this species from material forwarded to him by H.Hill, Napier. C. robertsii Hook. var. neglecta Massee is based on a specimen of Cordyceps robertsii parasitised by this fungus.