''Lithothelium grossum'' is a species of corticolous (bark-dwelling)

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Pyrenulaceae The Pyrenulaceae are a family of fungi in the order Pyrenulales. The family was first named by German botanist Gottlob Ludwig Rabenhorst in 1870. Species in the family have a widespread distribution, but are especially prevalent in the tropics, wh ...

. Found in China, it was formally described as a new species in 2006 by Dutch lichenologist

André Aptroot André Aptroot (Heemskerk, 1961) is a Dutch mycologist and lichenologist. In 1993 he did his PhD at the University of Utrecht under the supervision of Robbert Gradstein (nl). His dissertation was titled "Systematic studies on pyrenocarpous li ...

. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was collected in the Xishuangbanna Tropical Botanical Garden (

Mengla County Mengla County (; Tai Lue: , ''Mueang La''; lo, ເມືອງລ້າ; th, เมืองล้า) is a county under the jurisdiction of the Xishuangbanna Dai Autonomous Prefecture, in far southern Yunnan province, China. ''Meng'' is a vari ...

Yunnan Yunnan , () is a landlocked Provinces of China, province in Southwest China, the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is ...

) at an altitude of ; here it was found growing on a tree trunk. ''Lithothelium grossum'' is characterized by its large

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

(translucent)

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

s, which measure 27–37 by 12–17

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

; these are the largest of hyaline-spored species in genus ''

Lithothelium ''Lithothelium'' is a genus of lichen-forming fungi in the family Pyrenulaceae. Most of the species are found in tropical climates, and are usually corticolous (bark-dwelling) or saxicolous (rock-dwelling). The genus was circumscribed by Swi ...

''.

References

Eurotiomycetes Lichen species Lichens described in 2006 Lichens of China Taxa named by André Aptroot {{Eurotiomycetes-stub