''Lagerheimia'' 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 ...

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

in the family

Oocystaceae Oocystaceae is a family of green algae, in the order Chlorellales. The type genus is '' Oocystis''. List of genera , AlgaeBase accepted the following genera: *'' Amphikrikos'' Korshikov – 6 species *'' Catenocystis'' F.Hindák – 2 specie ...

. It is commonly found in

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 all over the world, although some species are rare and have only been recorded from Europe or the United States. The genus name of ''Lagerheimia'' is in honour of

Nils Gustaf Lagerheim Nils Gustaf Lagerheim (1860–1926) was a Swedish botanist, mycologist, phycologist, and pteridologist. Today, he is best remembered as one of the chief architects of pollen analysis as a tool in botany, alongside his student Ernst Post. In 1 ...

(1860–1926), who was a Swedish botanist, mycologist, phycologist, and

pteridologist #REDIRECTFern 01 Ferns Pteridologist #REDIRECTFern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The ...

. The genus 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 ...

Giovanni Battista De Toni Giovanni Battista de Toni (2 January 1864, Venice – 31 July 1924, Modena) was an Italian botanist, mycologist and phycologist. In 1885 he graduated from the University of Padua, where he studied natural sciences and chemistry with Pier Andre ...

and

Robert Hippolyte Chodat Robert Hippolyte Chodat (4 June 1865, Moutier – 28 April 1934) was a Swiss botanist and phycologist who was a professor and director of the botanical institute at the University of Geneva. He studied medicine and botany at Geneva, where he was l ...

in Nuova Notarisia vol.6 on page 86-90 in 1895.

Description

''Lagerheimia'' consists of solitary cells. Cells are spherical, ellipsoidal, ovoid, polyhedral, or citriform (lemon-shaped), with one to several spines at the poles; some species also have spines at the equators. A layer of mucilage around the cell may be present. Cells contain a parietal

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

with one pyrenoid. Species identification is based on the shape of the cells, placement and length of the spines, and presence or absence of tubercles at the base of the spines. Species with tubercles at the base of their spines have been classified in a separate genus, called ''Chodatella''; however, modern authors do not recognize this split. The genus is similar to ''

Franceia ''Franceia'' is a genus of green algae belonging to the family Oocystaceae. The genus was first described by Ernst Lemmermann Ernst Johann Lemmermann (27 May 1867 in Bremen – 11 May 1915 in Bremen) was a German botanist who specialize ...

'', which has spines distributed all over the cell surface. It may also be confused with single-celled forms of '' Desmodesmus'', a genus that usually has coenobia of four or eight cells.

Reproduction

''Lagerheimia'' reproduces asexually by

zoospore A zoospore is a motile asexual spore that uses a flagellum for locomotion. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves. Diversity Flagella types Zoospores may possess one or mo ...

s or

autospore An autospore is a non-motile (non-flagellated) aplanospore that is produced within a parent cell, and has the same shape as the parent cell, before release. Autospores, in addition to zoospore and aplanospore, are one of the three types of spore ...

s. Zoospores have two

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

. When reproducing with autospores, 2, 4, or 8 are formed within the mother cell and are released when the mother cell wall ruptures. Reports of

sexual reproduction Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...

have not been confirmed.

Taxonomy

''Lagerheimia'' is placed in the family ''

''. The cell wall

ultrastructure Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a co ...

of '' Lagerheimia subsalsa'' is similar to that of some species of ''

Oocystis ''Oocystis'' is a planktonic genus of mostly freshwater green algae of the family Oocystaceae.See the NCBIbr>webpage on Oocystis Data extracted from the The type species In zoological nomenclature, a type species (''species typica'') is th ...

'', and consists of several layers of microfibrils. Microfibrils are perpendicular from one layer to the next. Because ''Lagerheimia'' appears similar to one-celled forms of ''Desmodesmus'', some authors have doubted the validity of this genus. However, ''Lagerheimia'' strains are phylogenetically placed within the class Trebouxiophyceae. In its current circumscription, ''Lagerheimia'' is polyphyletic: some species are more closely related to ''

'' than to other ''Lagerheimia'' species.

References

External links

{{Taxonbar, from=Q6472018 Trebouxiophyceae genera Trebouxiophyceae Oocystaceae