Neophyllis

Neophyllis species are distinctive lichens characterised by their small, leaf-like structures (called squamules) and black, spherical spore-producing structures (apothecia). The squamules can range from flat and elongated to more cylindrical and coral-like in form, typically appearing bright green to olive-coloured when wet, and shifting to yellowish-green or brownish when dry, often with a glossy surface.^[5]

The genus has several distinctive microscopic features that set it apart from other lichens. It contains a green algal partner (photobiont) with round cells measuring 7–11 micrometres (μm) in diameter. The spore-producing structures (asci) contain specialised cells that produce eight spores each and have a unique internal structure that helps identify the genus. These spores are transparent, elliptical in shape, and lack a gelatinous outer coating.^[5]

The two species in the genus can be distinguished from each other both by their appearance and their chemistry. N. melacarpa, the more common species, typically forms extensive colonies that can spread over several square metres. Its squamules are relatively delicate and often develop finger-like projections that are very brittle. In sun-exposed locations, it can form dense cushions of upright, cylindrical lobes. The species produces a chemical compound called grayanic acid, often alongside other related substances.^[5]

Neophyllis pachyphylla, in contrast, tends to be more robust in appearance. Its squamules are thicker and more scattered, often resembling small tongues with slightly thickened, rounded tips. While it can also develop cylindrical projections, these never dominate the overall appearance of the lichen as they do in N. melacarpa. This species is chemically distinct, producing only melacarpic acid as its main compound.^[5]

Both species produce black, globe-shaped apothecia that can reach up to 1.5 mm in width. These reproductive structures either nestle among the squamules or are elevated above them on short stalks. When viewed under a microscope, these structures contain a dark chocolate-brown layer at their surface and produce transparent spores that are crucial for species identification.^[5]

Neophyllis is a distinctly Australasian genus, occurring in southeastern Australia, Tasmania, and New Zealand. The distribution and habitat preferences of its two recognised species differ distinctly. N. melacarpa is common and widespread throughout its range, showing considerable ecological versatility. It occurs across a variety of vegetation communities including rainforest, sclerophyll forest, woodland, and heathland. In shaded forest environments, it typically grows on wood, particularly favouring rotting logs, buttresses and stumps of old eucalypts, as well as the trunks of Nothofagus and Athrotaxis trees that provide soft, moisture-retaining substrates. In more exposed, sunny locations, particularly in high-rainfall areas of western and southwestern Tasmania, the species can be found growing on soil in various settings, including crevices of quartzitic boulders, buttongrass (Gymnoschoenus sphaerocephalus) moorland, alpine or subalpine heathland, and coastal granite outcrops. It has also been documented on Triassic sandstone formations in southeastern Tasmania.^[5]

In contrast, N. pachyphylla is considerably rarer and has been documented from only a few regions: the Grampians in Victoria, parts of eastern Tasmania, and the Southern Tablelands of New South Wales. Unlike its more common relative, N. pachyphylla is more substrate-specific. It occurs primarily on Devonian granite in Tasmania and on coarse sandy or gravelly soil over granite or sandstone in other locations. The species shows a particular preference for shaded rocks subject to moisture seepage and areas where silt accumulates in drainage channels on large rock outcrops. While N. melacarpa frequently occurs on wood, N. pachyphylla has never been observed on woody substrates.^[5]