Stirtonia (lichen)
Stirtonia is a genus of lichen-forming fungi in the family Arthoniaceae. It contains 22 species of corticolous crustose lichens found primarily in tropical regions.
Taxonomy
The genus was circumscribed by the British lichenologist Annie Lorrain Smith in 1926, with Stirtonia obvallata assigned as the type species. The species epithet honours the Scottish lichenologist James Stirton.Description
The thallus of Stirtonia contains green algae as its partner. These algae belong to the genus Trentepohlia and are responsible for photosynthesis within the lichen symbiosis. Stirtonia lichens reproduce sexually through spore-producing structures called asci. These asci are found in specialised areas of the thallus known as areas. A distinctive feature of Stirtonia is the presence of interascal hyphae that anastomose, or interconnect, forming a network. These hyphae are similar in appearance to the hyphae found in non-reproductive parts of the thallus and are not bound together by a jelly-like substance as seen in some other lichen genera.The of Stirtonia have a unique structure. They are divided only by transverse septa, creating several segments along the length of the spore. The walls of these spores, including the septa, are thickened. This thickening results in the internal chambers of the spores having a rounded or lens-like shape when viewed under a microscope.
Species
, Species Fungorum accepts 22 species of Stirtonia.Stirtonia borinquensis Stirtonia byssoidea – FloridaStirtonia caribaea Stirtonia coei – FloridaStirtonia curvata Stirtonia divaricatica – FloridaStirtonia epiphylla – SeychellesStirtonia ghattensis – IndiaStirtonia ibirapuitensis Stirtonia isidiata Stirtonia juaensis Stirtonia latispora – FloridaStirtonia lucida – BrazilStirtonia microspora Stirtonia neotropica Stirtonia nitida Stirtonia nivea Stirtonia obvallata Stirtonia ochracea – BrazilStirtonia psoromica Stirtonia punctiformis Stirtonia rhizophorae Stirtonia schummii- ''Stirtonia viridis''