''Thelomma santessonii'', the tan nipple lichen,
is a species of
saxicolous
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...
(rock-dwelling),
crustose lichen
Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichen ...
in the family
Caliciaceae
The Caliciaceae are a family (taxonomy), family of mostly lichen-forming fungus, fungi belonging to the class (taxonomy), class Lecanoromycetes in the division (mycology), division Ascomycota. Although the family has had its classification chan ...
. Found in northern North America, it was
formally described
A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...
as a new species in 1976 by lichenologist
Leif Tibell
Leif Tibell (born 16 November 1944) is a Swedish lichenologist and Emeritus Professor at the University of Uppsala. He is known for his expertise on calicioid lichens. He was awarded the Acharius Medal in 2012 for lifetime achievements in lich ...
.
It is
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to the coast and islands of
Southern California
Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...
and
Baja California
Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...
in Mexico.
''Thelomma santessonii'' has a yellowish
tan color, and is
areolate
Lichens are symbiotic organisms made up of multiple species: a fungus, one or more photobionts (an alga and/or a cyanobacteria) and sometimes a yeast. They are regularly grouped by their external appearance – a characteristic known as their gro ...
. The thallus has that measure up to broad. The expected results of
chemical spot tests are KC− on the
thallus
Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...
, and K+ (red), P+ (yellow) on the . When a long-wavelength
UV light
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of t ...
is lit on the thallus, it
fluoresce
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with color ...
s a blue-white color. The
ascospore
In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...
s of the lichen are spherical and lack any
septa
SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...
; they measure 14–16
μm
The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...
.
''
Endococcus thelommatis'' is a
lichenicolous fungus
A lichenicolous fungus is a member of a specialised group of fungi that live exclusively on lichens as their host organisms. These fungi, comprising over 2,000 known species across 280 genera, exhibit a wide range of ecological strategies, includ ...
that parasitizes ''Thelomma santessonii''.
References
Caliciales
Lichen species
Lichens described in 1976
Lichens of the Southwestern United States
Lichens of Mexico
Taxa named by Leif Tibell
{{Caliciales-stub