Austropeltum Bunodophoron Calycidium Gilbertaria Leifidium Neophyllis Sphaerophorus The Sphaerophoraceae are a family of lichen-forming fungi in the order Lecanorales.

[3] The family, which was proposed by Elias Magnus Fries in 1831, is characterised by its distinctive boundary tissue that separates generative and vegetative parts, and includes species with various growth forms ranging from shrub-like (fruticose) to crusty (crustose).

Most members produce mazaedia, specialised spore-dispersing structures typically found at branch tips, though some genera have different reproductive strategies.

While traditionally defined by fruticose growth forms and mazaedial reproduction, modern molecular studies have expanded the family's concept to include morphologically diverse genera like the crustose Gilbertaria.

[4] By the late 18th century, only a few species now classified in this family were known to science, including Lichen fragilis (described by Carl Linnaeus in 1753) and L. globosus (described by William Hudson in 1762).

This structure, consisting of pigmented hyphae with a high concentration of cytoplasmic material, separates generative and vegetative tissues and has been proposed as a synapomorphy (shared derived characteristic) that unites the family.

Both families are part of a broader clade of mazaedia-producing lichens, underscoring the importance of passive spore dispersal in their evolutionary history.

The ability to form mazaedia has evolved independently multiple times in Ascomycota, including at least 14 instances within Lecanoromycetes, highlighting the ecological and evolutionary significance of this spore dispersal strategy.

The prototunicate ascus, previously regarded as primitive, is now understood to have evolved through the reduction of tube-like structures characteristic of other members of Lecanorales.

Molecular studies suggest a potential sister relationship with Bacidiaceae and Psoraceae, but these connections lack robust statistical support.

Members display diverse reproductive structures, including mazaedia in traditional genera, lecideine apothecia in some species, and various types of apothecial stalks (e.g., podetia and pseudopodetia).

Many grow in a shrub-like (fruticose) manner, either upright or spreading across surfaces, while others form scale-like, shield-shaped, or crusty growths on their substrate.

Mazaedia-producing genera like Sphaerophorus and Bunodophoron begin reproductive development with the formation of a globose, plasma-rich primordium beneath the thallus cortex.

This characteristic is especially prominent in Leifidium tenerum, where the tissue develops early, forming a lens-like structure that supports the hymenium during spore dispersal.

While Neophyllis retains some similarities to mazaedia-producing genera, including the formation of a pigmented boundary tissue, Austropeltum develops simpler apothecia that lack the generative tissue-derived layer found in other members of the family.

[12] The cortex (outer layer) ranges from 45–200 μm thick and is composed of thick-walled, gelatinised, fused hyphae covered by a thin epicortex.

[6] Like all lichens, Sphaerophoraceae species represent a partnership between a fungus and an alga, specifically containing green algal partners (chlorococcoid photobionts).

[11] Some species of Bunodophoron, such as B. macrocarpum and B. scrobiculatum, have what could be interpreted as a dimorphic thallus, where flattened thalli bear apothecia on marginal branches that are subterete and variably developed.

While the bitunicate ascus type is considered derived (advanced) within the Lecanorales, the Sphaerophoraceae appears to have secondarily lost this feature, adopting the simpler prototunicate condition instead.

The ornamentation appears greenish in potassium hydroxide (KOH) solution and reddish in nitric acid, aiding chemical identification.

Neophyllis exhibits a two-layered boundary tissue similar to mazaedia-producing genera, but with weaker pigmentation, while Austropeltum lacks the generative tissue-derived layer entirely.

Conversely, the simpler boundary tissues in non-mazaedia-producing genera like Austropeltum and Neophyllis may reflect a reduced need for spore protection in their less exposed habitats.

The family shows notable diversity in subantarctic regions and cool temperate forests, with several species exhibiting disjunct distributions between southern South America, Australia, and New Zealand.