''Haematomma ochroleucum'', also known as yellow bloodstain lichen, is a species of

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 ...

ized fungus. First described in 1771 by

Noël Martin Joseph de Necker Noël Martin Joseph Necker (25 December 1730 – 30 December 1793) was a Belgian physician and botanist. Career Necker was the personal physician to the court of the Electoral Palatinate in Mannheim. His botanical was work involved the study o ...

, it has no subspecies, but two named varieties: ''H. o.'' var. ''ochroleucum'' and ''H. o.'' var. ''porphyrium''.

Taxonomy

Belgian botanist

first described ''Haematomma ochroleucum'' in 1771 from a

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 ...

collected from shaded rocks in the Rheinland-Pfalz region of Germany. He named it ''Lichen ochroleucus''. When

Jack Laundon Jack Rodney Laundon (28 July 1934 – 31 December 2016) was a British lichenologist and became President of the British Lichen Society. Education and personal life Jack Rodney Laundon was born 28 July 1934 in Kettering, Northamptonshire. He was ...

moved the species to the genus ''

Haematomma ''Haematomma'' is a genus of crustose lichens established by Abramo Bartolommeo Massalongo in 1852. It is the sole genus in the Haematommataceae, a family circumscribed by Josef Hafellner in 1984. Commonly called bloodstain lichens, the species ...

'' in 1970, he created the combination ''Haematomma ochroleucum'' to replace the illegitimately named ''Haematomma coccineum''. The latter name had been given to a later description of the same species, and had gained widespread usage; however, Necker's name took taxonomic precedence. ''Haematomma ochroleucum'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

for the genus ''Haematomma''. It has no

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

, but it does have two named varieties: ''H. o.'' var. ''ochroleucum'' and ''H. o.'' var. ''porphyrium'', which differ in color and chemical composition. The genus name ''Haematomma'' means "bloody eye", and is a reference to the red color of the lichen's apothecia. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''ochroleucum'' is a combination of the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word ''oclira'', meaning "ochre", and the Greek word ''leucum'', meaning "white"; the combination indicates a pale

ochre Ochre ( ; , ), or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the colours produced ...

color. The species is known colloquially as ''yellow bloodstain lichen''.

Description

''Haematomma ochroleucum'' is a

. It comes in two color forms: the

thallus Thallus (plural: 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. Many of these organisms wer ...

of ''H. o. ochroleucum'' is pale yellow to yellow-green, while that of ''H. o. porphyrium'' is whitish to pale gray. Colonies of both varieties are edged with a fringed white prothallus. Its

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.chlorococcoid. The lichen's thallus reacts positively with both

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp ...

(K) and para-phenylenediamene (Pd), turning yellow in both cases. Its apothecia react positively with potassium as well, turning purple. Among the substances produced by the lichen are atranorin,

zeorin Zeorin is a triterpene with the molecular formula C30H52O2 which occurs in many lichens A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among hypha, filaments of multiple fungus, fungi species in a mutu ...

, and porphyrillic acid. The variety ''ochroleucum'' also produces

usnic acid Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933-1937 by Curd and Robertson. Usnic a ...

, which the variety ''porphyrium'' does not. The apothecia and pycnidia produce anthraquinones.

Similar species

''Haematomma ochroleucum'' var. ''ochroleucum'' can look very similar to '' Lecanora thysanophora'', but the former species has a shorter, more continuous prothallus which is more uniformly white with thinner

hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

. The two species share similar chemistry, though '' Lecanora thysanophora'' nearly always contains thysanophora unknowns that are not known to occur in ''Haematomma ochroleucum''.

Distribution and habitat

In Europe, ''Haematomma ochroleucum'' has been reported as widespread, though its relative abundance varies widely. In parts of Ireland and Wales, it is rare but locally abundant on shaded rocky outcrops, particularly those that are north-facing. In Wales, it is more common inland than at the coast. In Belgium and Luxembourg, it is found primarily on protected, vertical surfaces on siliceous or

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

rocks, or on the bark of older

beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

trees in well-preserved forests. It is less common on the trunks of poplars and

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...

s. In North America, it is rare, and limited primarily to the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

and southern

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

. There, it is found primarily in waterfall spray zones, with fewer colonies on drier vertical rock faces, rocky overhangs, and the trunks of large black cottonwood trees. It has also been found in Maine.

Ecology

''Haematomma ochroleucum'' cannot tolerate significant amounts of

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...

pollution; it is found only if the mean winter concentrations are less than about 60 μg/m³. In Ireland, it grows in communities that include '' Lobaria virens'', '' Nephroma laevigatum'', '' Opegrapha gyrocarpa'', ''

Dermatocarpon luridum ''Dermatocarpon luridum'' is a species of lichen belonging to the family Verrucariaceae The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the ...

'' and '' Toninia pulvinata''. On the Danish island of

Bornholm Bornholm () is a Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland. Strategically located, Bornholm has been fought over for centuries. It has usually been ruled by ...

(in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

), it occurs on vertical rock faces above high, in association with ''

Ramalina siliquosa ''Ramalina siliquosa'', also known as sea ivory, is a tufted and branched lichen which is widely found on siliceous rock (geology), rocks and stone walls on coastlands round the British Isles, occasionally slightly inland. It grows well above th ...

'', ''

Lecanora atra ''Tephromela atra'' is a species of lichen in the family Tephromelataceae. It has a worldwide distribution. Synonyms ''Tephromela atra'' has many synonym since many previously described species have been reclassified as ''T. atra.'' These includ ...

'', and '' Rhizocarpon constrictum''.

References

External links

* * {{Taxonbar, from=Q10431449 ochroleucum Lichen species Lichens described in 1771 Taxa named by Noël Martin Joseph de Necker Lichens of Central Europe Lichens of Northern Europe Lichens of the Northwestern United States Lichens of the Northeastern United States