Holotype (PDD 27085); Isotype (Herb. HK. ZT 69/78: 'Track to Wilberg, SE of Hari Hari, Prov. Westland, N.Z.; leg. Horak, 15.II.1969'.

Pileus 10-20 mm diam., convex becoming umbonate to campanulate, margin upturned in aged carpophores, deep green at the centre, yellow towards the estriate margin, reddish-brown drying out, not hygrophanous, dry. Lamellae decurrent, lemon yellow to greenish-yellow, moderately distant, gill edge concolorous. Stipe 20-35 x 1-2 mm, cylindric or attenuated towards the base, yellowish above, deeper coloured at the base, finally becoming pinkish, glabrous, dry, hollow, single or fasciculate. Context greenish in the pileus. Odor and taste not distinctive. Chemical reaction on pileus: KOH, HCl and NH3 - green colours of the pileus fading immediately. Spores 6-8 x 4-4.5 µm, ellipsoid, smooth, inamyloid. Basidia 35-42 x 7µ,  4-spored. Cystidia absent. Cuticle a cutis of repent, cylindric hyphae (3-6 µm diam.), membrane not gelatinized, subcutis-subcellular. Clamp connections absent.

In soil under Weinmannia, Schefflera, Aristotelia, Fuchsia, etc. New. Zealand.

Pileo 10-20 mm lato, ex umbonato-convexo concavo, viridi-luteo, sicco. Lamellis arcuato-decurrentibus, limoneis vel viridi-luteis. 8tipite 20-35 x 1-2 mm, cylindraceo vel attenuato basim versus, luteolo, sicco. Sporis 6-8 x 44.5 µm, ellipticis. Cystidiis nullis. Epicute ex hyphis repentibus cylindraceisque cutem formantibus, fibulis nullis. Ad terram in silvis. Novazelandia.

This species has the colours of Gl. psittacinus (Fr.) but its spores are considerably smaller and neither pileus nor stipe are glutinous. A species closely related to H. luteovirens is reported from Japan. However, H. olivaceo-viridis Hongo (1967) differs from the N.Z. species by its emarginate-adnate lamellae, its more conic pileus, its habitat, and microscopical characters of the hyphae composing the cuticle.

Holotypus (PDD 27085): 'Wilberg, Hari Hari, N.Z.; leg. Horak, 15.II.1969'.