The family is characterised by pale-coloured thalli, apothecia (fruiting bodies) that are typically pale but may darken with age, and ascospores that vary in shape and septation.

Members of the Ramalinaceae are found in a wide range of habitats worldwide, from coastal fog deserts to boreal, temperate, and tropical forests.

Some genera, such as Namibialina, Vermilacinia, and Niebla, are endemic to specific coastal desert regions, whilst others like Ramalina have an almost worldwide distribution.

[2] According to the nomenclatural authority Index Fungorum, while Agardh initially classified it as an "ordo" (order), he used it in a way that suggested a family ranking, referring to it as "Ramalineae".

The research revealed that the fruticose genera within Ramalinaceae are not monophyletic (derived from a single ancestor) but form two distinct lineages: 1) Ramalina + Namibialina and 2) Vermilacinia + Niebla.

[6] The study highlighted challenges in delimiting species boundaries within Niebla and Vermilacinia, indicating that more data are required for a comprehensive understanding.

Notably, the taxonomy proposed by Spjut (1996) for Niebla was not fully corroborated by molecular data, whereas that for saxicolous Vermilacinia received substantial support.

Species lacking secondary metabolites (except usnic acid) were resolved at the base of the phylogenetic tree but did not form a monophyletic group.

The thallus, which is the body of the lichen, can take different forms such as crusty (crustose), bushy (fruticose), scale-like (squamulose), or even granular (leprose) or cottony (byssoid).

The lichen's photobiont partner, which is the photosynthetic organism living within the fungus, is of the chlorococcoid type, meaning it consists of green algae that are spherical or slightly elongated.

The edge of the apothecium (the margin) typically lacks a thallus-like covering, but a structural layer called the exciple is often present, though it may disappear over time as the lichen matures.

These asci belong to either the Bacidia or Biatora types, which are distinguished by specific staining patterns when exposed to iodine (K/I+), showing a dark blue reaction.

[10] Additionally, members of this family may produce asexual reproductive structures known as pycnidia, which are embedded in the lichen tissue or sit on the surface.

[12] Both T. jamesii and T. lynnae are known to form symbiotic relationships with lichens from other genera and families beyond Ramalinaceae, indicating their broader ecological importance.

[12] The Ramalinaceae family exhibits a diverse range of habitats and distributions, with several genera showing highly specialised ecological niches.

In contrast, Ramalina has a subcosmopolitan distribution, colonising a wide range of habitats from saxicolous sea-shores to trunks and branches in boreal, temperate, and tropical forests.

[71] Additionally, R. nematodes, although more abundant with twelve locations, is considered Near Threatened due to its very restricted area of occupancy and the potential impacts of the same threats.

It faces unique threats such as flash floods during El Niño events, erosion, and rising sea levels, which are expected to reduce its population size, area of occupancy, and habitat quality by up to 40% over the next 45 years.

Its limited distribution, confined to a single location with an area of occupancy up to 32 km², makes it susceptible to habitat transformation caused by invasive species and climate change, which could alter its natural sea-side low-shrub vegetation.

This site has experienced significant habitat loss due to logging and the expansion of urban, industrial, and agricultural frontiers.