Flora of New Zealand Series

Thallus of dark green to bright emerald green, gelatinous globules (to 0.1-0.2 mm diam.) or forming a ± continuous, gelatinous mat on exposed, damp soil. Each globule composed of clustered, elongate, green algal cells (Coccomyxa) surrounded by a sheath of fungal hyphae. Fruiting bodies an erect toadstool. Pileus small (usually under 2.5 mm broad but up to 4.5 mm), convex to plane, becoming depressed, sometimes infundibuliform, margin usually incurved at first, often striate when moist, surface hygrophanous or subhygrophanous, glabrous or fibrillose or scaly, colours bright or dull, mostly yellow or orange. Context very thin to thin, pliant to soft, fragile or brittle, watery when fresh. Lamellae distinctly decurrent, often slightly thickened and waxy, subdistant to distant, often arched, whitish or brightly coloured with shades of yellow or orange. Stipe slender, 3-6 mm wide, watery and soft or brittle, not viscid, often translucent, hollow or ± solid, surface glabrous or fibrillose to pubescent or hirsute, concolorous with lamellae of pileus or duller. Spores not amyloid, smooth, white in deposit or yellowish to pale salmon pink. Clamp connections present or absent.

Omphalina is a Basidomycete genus of c. 19 species some of which form lichenised associations with the green alga Coccomyxa, the lichenised associations being widely known as Coriscium viride or Botrydina vulgaris see Hawksworth et al. [ Lichenologist 12: 18 (1980)]. In New Zealand such lichenised associations are found in alpine areas, where the small, bright yellow or orange toadstools and their associated spreading, green, lichenised thalli are often seen in the summer along the sides of tracks, on damp soils, amongst mosses, or in bogs, or rarely on decaying tree boles in deep shade. The associations have not yet been closely studied in New Zealand and it is likely that undescribed taxa are involved. The present account discusses two Northern Hemisphere taxa as a guide to further work on New Zealand populations. The account of North American species [Bigelow Mycologia 62: 1-32 (1970)] contains much information.