Collema subconveniens

Collema subconveniens forms a soft, leafy (foliose) thallus up to 8 cm across. The thallus is membranous and closely attached to the substrate, though parts may lift and become slightly ascending. Its surface is smooth or only faintly ridged, and it bears sparse, scale-like isidia. The lobes are up to 8 mm wide, overlapping and often somewhat undulate, with a flat, matt to slightly glossy surface. When moist they are light grey-green to light olive-green, turning brown on drying. The species is usually richly fertile, with numerous laminal apothecia up to 1.5 mm in diameter. These are sessile with a slightly constricted base, and have a thin, entire thalline margin that may become inconspicuous with age. The apothecial disc is initially flat but often becomes convex, matt or occasionally shiny, and lacks any whitish frost (epruinose), varying in colour from pale red through dark red to brown. The asci measure 52–110 μm by 15–24 μm and contain ascospores 20–40 μm by 8–10.5 μm, which are fusiform to ellipsoidal, straight with pointed ends, and muriform with 3–5 transverse and 1–3 longitudinal septa, sometimes with strong constrictions. Asexual reproduction occurs through numerous laminal pycnidia up to 200 μm wide with a pale yellow pycnidial gel; they produce straight conidia 4–5 μm by 1–1.5 μm that are slightly swollen towards the ends.

Collema subconveniens is a corticolous lichen, growing on the bark of shrubs and trees. Beyond New Zealand and Australia, the lichen has been recorded in South America, Japan, and India. In Nepal, Collema subconveniens has been reported at 1,260 m elevation in a compilation of published records.

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