''Sticta'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s in the family

Peltigeraceae The Peltigeraceae are a family of lichens in the order Peltigerales. The Peltigeraceae, which contains 15 genera and about 600 species, has recently (2018) been emended to include the families Lobariaceae and Nephromataceae. Many Peltigeraceae sp ...

. The genus has a widespread distribution, especially in tropical areas, and includes about 114

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

. These lichens have a leafy appearance, and are colored brown or black. ''Sticta'' species with

cyanobacteria Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...

as photobionts can fix nitrogen from the atmosphere, and due to their relative abundance and high turnover, they contribute appreciably to the

rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

ecosystem. They are commonly called spotted felt lichens.

Description

The vegetative bodies of the ''Sticta'', the

thalli 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 ...

, are foliose, or leafy in appearance. They typically have dimensions of in diameter, although specimens with diameters of up to have been recorded. The lobes are rounded, and the upper surface is black or brown, while the lower surface has a light to dark brown layer of fine hairs (a ), with a few craters, called . Thalli often smell of shrimp or fish. The vegetative reproductive structures called

isidia An isidium (plural: isidia) is a tiny, wart- or finger-like outgrowth on the thallus surface of certain lichen species. It is one of two principal types of vegetative reproduction, vegetative reproductive structures in lichens, the other being ...

soredia Soredia are common reproduction, reproductive structures of lichens. Lichens asexual reproduction, reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungus, fung ...

are often present on species in this genus;

apothecia An ascocarp, or ascoma (: ascomata), 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. As ...

(cup-shaped spore-bearing structures) are rarely found. ''Sticta'' species are usually found growing on bark, wood, or mossy rock. partners of ''Sticta'' species include members of the

green algae The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...

genera '' Chloroidium'', ''

Coccomyxa ''Coccomyxa'' is a genus of green algae in the family Coccomyxaceae. This genus is defined by their small, elliptical to spherical shape, and the presence of a simple parietal chloroplast. These features, along with their occurrence in various l ...

'', ''

Elliptochloris ''Elliptochloris'' is a genus of green algae in the order Prasiolales. Species of this genus are common and found in a variety of terrestrial habitats such as soils. Some species in the genus are partners in lichens. One species, '' E. marina ...

'', '' Heveochlorella'', and '' Symbiochloris''. The

liverwort Liverworts are a group of non-vascular land plants forming the division Marchantiophyta (). They may also be referred to as hepatics. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry ...

genus ''

Monoclea ''Monoclea'' is a genus of liverwort that contains two species. It is the only genus in the family Monocleaceae. Species of this genus can be found in New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. ...

'' contains lichen-like organisms completely unrelated to, but readily confused with ''Sticta''.

Distribution and habitat

''Sticta'' species are primarily

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

in distribution, but some species have been reported from as north as Norway, and as far south as the southern tip of South America. Most species of ''Sticta'' grow on bark, wood, or mossy rock, usually in humid areas.

Phylogenetics

Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analysis of small and large

ribosomal RNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...

subunits has confirmed that the genus ''Sticta'' is

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

Indicators of ecological continuity

Some

epiphytic An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...

lichen species may be used as "ancient woodland indicators"; they can used to quantitatively assess the degree to which a forest has had a long history of

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an a ...

continuity. The presence of these species is a reliable indicator that the forest has existed back to early medieval times, without being

clear-cut Clearcutting, clearfelling or clearcut logging is a forestry/logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and seed tree harvests, it is used by foresters to create certain types of for ...

and regrown. Two ''Sticta'' species, namely, ''S. dufournii'' or the blue-green algal

morphotype In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the s ...

''S. canariensis'', are among several species of lichens that may be used to calculate the New Index of Ecological Continuity (NIEC), considered the most sensitive and accurate determination of forest continuity.

Bioactive compounds

A comprehensive comparative study on the antioxidant activity of lichens from Hawaii and Iceland revealed the Hawaiian lichen ''S. weigelii'' to be a potent producer of antioxidative compounds.

Species

*'' Sticta acyphellata'' – Hawaii *'' Sticta alpinotropica'' – Papua New Guinea *'' Sticta andina'' – Colombia *'' Sticta antoniana'' – Hawaii *'' Sticta aongstroemii'' – Brazil *'' Sticta arachnofuliginosa'' – Colombia *'' Sticta arbuscula'' – Colombia *'' Sticta arbusculotomentosa'' *'' Sticta arenosella'' *'' Sticta atlantica'' – Europe *'' Sticta atroandensis'' – Colombia *'' Sticta baileyi'' – Australia *'' Sticta borinquensis'' – Puerto Rico *'' Sticta brevior'' – Colombia *'' Sticta brevipes'' *'' Sticta caliginosa'' *'' Sticta camarae'' *'' Sticta canariensis'' *'' Sticta caperata'' *'' Sticta carolinensis'' *'' Sticta ciliata'' –

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeog ...

; Africa;

Macaronesia Macaronesia (; ) is a collection of four volcanic archipelagos in the Atlantic Ocean#North Atlantic, North Atlantic Ocean, off the coast of North Africa and Europe. Each archipelago is made up of a number of list of islands in the Atlantic Oc ...

; Western Europe *'' Sticta corymbosa'' – Puerto Rico *'' Sticta cyphellulata'' *'' Sticta dendroides'' *'' Sticta densiphyllidiata'' – Puerto Rico *'' Sticta deyana'' – North America *'' Sticta diversa'' *'' Sticta duplolimbata'' *'' Sticta emmanueliana'' – Hawaii *'' Sticta fasciculata'' *'' Sticta filix'' *'' Sticta flavireagens'' *'' Sticta flavocyphellata'' – Australia *'' Sticta flynnii'' – Hawaii *'' Sticta fragilinata'' *'' Sticta fuliginoides'' – Continental Europe;

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

References

Cited literature

* {{Taxonbar, from=Q7616341 Peltigerales genera Lichen genera Taxa described in 1791 Taxa named by Johann Christian Daniel von Schreber