Tetramelas
From Wikipedia, the free encyclopedia
| Tetramelas | |
|---|---|
 | |
| Tetramelas chloroleucus | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Caliciales |
| Family: | Caliciaceae |
| Genus: | Tetramelas Norman (1852) |
| Type species | |
| Tetramelas geophilus Norman (1853) | |
Tetramelas is a genus of lichen-forming fungi in the family Caliciaceae.[1] The genus is distinguished by its distinctive spores, which are divided into four compartments and turn brown as they mature, giving rise to the name Tetramelas from the Greek words for 'four' and 'dark'. These lichens typically form greyish crusts on rocks, bark, or other surfaces, with small black disc-shaped fruiting bodies that contain the characteristic four-chambered spores.
The genus was circumscribed in 1852 by the Norwegian botanist Johannes Musaeus Norman. In his original description, Norman characterized Tetramelas by its distinctive spores, which have cross-walls (septa) running transversely and are clearly divided into four compartments (quadrilocular). He noted that the spore wall becomes somewhat blunted or obtuse as the spores mature and develop their characteristic compartmented structure. The genus name Tetramelas derives from the Greek words τέτρα (tetra, meaning 'four') and μέλας (melas, meaning 'black' or 'dark').[2]
Norman described the fruiting bodies (apothecia) as resembling those found in the genera Lecidea or Biatora, indicating they have a similar disc-like structure with a dark margin. He distinguished Tetramelas from the related genus Dimaura (now known as Catolechia[3]) by several key features, noting that while both genera shared some similarities, Tetramelas was particularly close to the section Sticella of Dimaura and showed connections to both the red Sticella series and the Secoliga group.[2]
Norman established the genus with two species: Tetramelas geophilus (originally described by Sommerfelt) and Tetramelas querneus (originally described by Dickson).[2]
