''Hydropunctaria'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

saxicolous A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, give ...

(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 ...

s in 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 family, have a wide variety of thallus forms, and include crustose (crust-like), foliose ( ...

. The genus includes both aquatic and amphibious species, with members that colonise either

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

habitats. The type species, '' Hydropunctaria maura'', was formerly classified in the large genus ''

Verrucaria ''Verrucaria'' is a genus of lichenized (lichen-forming) fungi in the family Verrucariaceae. Taxonomy The genus was circumscribed by German botanist Heinrich Adolph Schrader in 1794, with '' Verrucaria rupestris'' assigned as the type species. I ...

''. It is a widely distributed species common to

littoral zone The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

s. Including the type species, five ''Hydropunctaria'' lichens are considered marine species: ''H. adriatica'', ''H. amphibia'', ''H. aractina'', ''H. orae'', and ''H. oceanica''.

Taxonomy

''Hydropunctaria'' was

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

in 2009 by Christine Keller,

Cécile Gueidan Cécile Gueidan is a mycologist and lichenologist who applies morphological and molecular biological methods to the origin and taxonomy of fungi that live in lichen symbioses and within rocks. Early life and education Gueidan began working on ...

, and Holger Thüs, with '' Hydropunctaria maura'' assigned as 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 ...

Description

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 ''Hydropunctaria'' is crustose, with a form ranging from continuous (more or less unbroken) to

rimose ''Rimose'' is an adjective used to describe a surface that is cracked or fissured.areolate Lichens are composite organisms made up of multiple species: a fungal partner, one or more photosynthetic partners, and sometimes a basidiomycete yeast. They are regularly grouped by their external appearance – a characteristic known as their ...

. In some species the texture of the thallus is somewhat gelatinous. Documented thallus colours include yellowish-brown, green, and dark grayish

olive The olive, botanical name ''Olea europaea'', meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as ''Olea europaea'' ...

to black. The upper

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

is only weakly separated into distinct layers; microscopically, it comprises cortical cells with a diameter typically smaller than the fungal cells from the algal layer. The uppermost layer of cortical cells, when present, often contain yellowish to brown or olive-blackish

pigments A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

; this characteristic, however, is not always consistent, as evidenced by the colourless specimens sometimes collected from shaded sites. Black dots (''punctae'') are sometimes visible at the surface of the thallus—more readily so in wet thalli. The layer of algal cells is not clearly differentiated from the upper cortex, although generally they are usually arranged in vertical columns, occasionally interrupted by black punctae. The

medulla Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of th ...

is paraplectenchymatous (fungal tissue with a cellular structure superficially like

parenchyma Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word π ...

vascular plants Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...

) and is sometimes very thin or absent, often replaced by a black carbonaceous layer that interrupted by isolated black punctae or columns. Hydropunctaria maura 77786203

Perithecia An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mo ...

(flask-shaped

ascomata An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mo ...

opening by a pore, or

ostiole An ''ostiole'' is a small hole or opening through which algae or fungi release their mature spores. The word is a diminutive of "ostium", "opening". The term is also used in higher plants, for example to denote the opening of the involuted ...

) are immersed (or partially so) in the thallus. The involucrellum refers to the upper, often exposed covering or cap external to the excipulum and usually distinct from it. In ''Hydropunctaria'', the involucrellum is black, often with a rough or uneven upper surface, and it can be of several forms: apical (where the involucrellum occurs only around the ostiole, but extends some distance laterally) to dimidiate (where the involucrellum covers only the upper portion of the perithecium) or entire (where the involucrellum completely surrounds the perithecium). The excipulum (the cup-shaped layer of tissue surrounding the

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...

) is either pale with a brown ostiole or completely pigmented. ''Hydropunctaria'' species have eight-spored

asci ASCI or Asci may refer to: * Advertising Standards Council of India * Asci, the plural of ascus, in fungal anatomy * Accelerated Strategic Computing Initiative * American Society for Clinical Investigation * Argus Sour Crude Index * Association of ...

that are bitunicate (i.e., with two functional ascal wall layers). Its

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 are simple (i.e., lacking

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

), with a rounded or

ellipsoid An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...

shape and a length usually more than 12

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 ...

Species

*'' Hydropunctaria adriatica'' *'' Hydropunctaria alaskana'' –

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

*'' Hydropunctaria amphibia'' *'' Hydropunctaria aractina'' *'' Hydropunctaria maura'' *'' Hydropunctaria oceanica'' *'' Hydropunctaria orae'' *'' Hydropunctaria rheitrophila'' *'' Hydropunctaria scabra'' *'' Hydropunctaria symbalana''

Species interactions

Lichenicolous A lichenicolous fungus is a parasitic fungus that only lives on lichen as the host. A lichenicolous fungus is not the same as the fungus that is the component of the lichen, which is known as a lichenized fungus. They are most commonly specific to ...

(lichen-dwelling) lichens recorded growing on ''Hydropunctaria'' include '' Sirenophila ovis-atra'' and '' Flavoplaca microthallina''.

References

{{Taxonbar, from=Q10528934 Verrucariales Lichen genera Taxa described in 2009 Eurotiomycetes genera Taxa named by Cécile Gueidan