''Crustospathula'' 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 ...

of five 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 ...

s in the family

Malmideaceae Malmideaceae is a family of crustose and corticolous lichens in the order Lecanorales. It contains eight genera and about 70 species. Taxonomy Malmideaceae was created in 2011 to accommodate a group of species, formerly placed in genus ''Malcolm ...

. They are characterized by their stalked and sometimes branched cartilaginous soredia and ''

Bacidia ''Bacidia'' is a genus of lichen-forming fungi in the family Ramalinaceae. The genus was circumscribed by Giuseppe De Notaris in 1846. Species in the genus are crust-like lichens with stemless apothecia; they have green algae (chloroccoid) as p ...

''-like apothecia.

Taxonomy

''Crustospathula'' 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 ...

by 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 ...

in 1998, with '' Crustospathula cartilaginea'' 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 ...

. This species was discovered by Aptroot in Madang Province,

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

in an undisturbed

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

lowland rain forest. It was, according to Aptroot, the known instance of a

with stalked, cartilaginous, labriform

soralia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria o ...

. For this reason, it could not be assigned to any known genera, and ''Crustospathula'' was created to hold it. Aptroot initially assigned the genus tentatively to the family Bacidiaceae, because of the resemblance of generative structures with certain species of ''

''. It was later in the Ramalinaceae, until

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

analysis determined that its true placement belonged in the Malmideaceae.

Description

''Crustospathula'' species are

crustose Crustose is a habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. ''Crustose'' adheres very closely to the substrates at all points. ''Crustose'' is found on rocks and ...

with stalked and cartilaginous soredia that are labriform (lip-shaped) or crenately (scalloped) lobed. The

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 rod-shaped and often curved or bent. They contain between 0 and 3

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 ...

, and measure 20–25 by 0.8–1.5 um. The lichens contain the

secondary Secondary may refer to: Science and nature * Secondary emission, of particles ** Secondary electrons, electrons generated as ionization products * The secondary winding, or the electrical or electronic circuit connected to the secondary winding i ...

compounds atranorin and 2'-O-methylperlatolic acid.

Species

*'' Crustospathula amazonica'' Aptroot, M.Cáceres & Timdal (2014) – Brazil *'' Crustospathula cartilaginea'' Aptroot (1998) – Papua New Guinea *'' Crustospathula humboldtii'' Kalb (2011) – Venezuela *'' Crustospathula khaoyaiana'' Kalb & Mongk. (2012) – Thailand *'' Crustospathula macrocarpa'' Aptroot & Schumm (2009) – Philippines

References

{{Taxonbar, from=Q5190267 Malmideaceae Lichen genera Lecanorales genera Taxa described in 1998 Taxa named by André Aptroot