''Lunularia'' 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 ...

liverworts Liverworts are a group of non-vascular plant, non-vascular embryophyte, 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 wh ...

whose only species is ''Lunularia cruciata'', the crescent-cup liverwort. ''Lunularia'' is either the only genus in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Lunulariales, or may be placed in the order

Marchantiales Marchantiales is an order of thallose liverworts (also known as "complex thalloid liverworts") that includes species like '' Marchantia polymorpha'', a widespread plant often found beside rivers, and '' Lunularia cruciata'', a common and often t ...

. The name, from

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''luna'', moon, refers to the moon-shaped gemma cups.

Description

''Lunularia cruciata'' grows large, dichotomously branched green

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 ...

with crescent shaped gemma cups containing disc-like gemmae. This is a unique morphological characteristic not possessed by other thalloid liverworts. Its thallus surface is shiny, faintly lined, and is dotted with tiny air pores. When dried the thallus turns yellowish in color and its margin rolls inward. Lunularia cruciata archegonial head with sporophytes from Haeckel Hepaticae

Lunularia cruciata archegonial head with sporophytes from Haeckel Hepaticae

As in other liverworts, the main plant body or

thallus 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 ...

is a

haploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the num ...

gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the se ...

. The antheridia of ''L. cruciata'' develops in early spring, the

archegonia An archegonium (: archegonia), from the Ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamet ...

develops in spring and sporophytes develop in late summer. However, records of sporophyte developments and sexual reproduction are rare and scattered. This was suspected to have been the result of the anthropogenic spreading of this species, causing a disjunctive distribution of antheridia and archegonia. When reproducing sexually, the four archegonia is arranged in a cross-shaped head (hence the specific name ''cruciata'') bearing

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

sporophyte plantlets. When reproducing asexually, the disc-shaped gemmae are readily dislodged from the cups by splashes of rainwater. They can then quickly "take root" and start to grow in suitably damp places, which is why they are so successful in greenhouses.

Distribution

''Lunularia cruciata'' is distributed across the world, found in continents including

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Australasia Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different context ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, the

Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...

, and

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

. It occurs commonly in western Europe, and is native to the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

region, where the morphological forms from sexual reproduction are more frequently found there. It is also common in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, where it now grows "wild", and is known as an introduced weed in gardens and greenhouses in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

.Schuster, Rudolf M. ''The Hepaticae and Anthocerotae of North America'', volume VI, pages 80-91. (Chicago: Field Museum of Natural History, 1992). . Ella Orr Campbell believed that ''L. cruciata'' was introduced into

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

sometime after 1867. The

sporophyte A sporophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the biological life cycle, life cycles of plants and algae. It is a diploid multicellular organism which produces asexual Spo ...

s of ''L. cruciata'' are rare, but has been found in European regions, as well as in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

, California,

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and New Zealand.

Habitat and ecology

''Lunularia cruciata'' grows in damp, shaded and disturbed habitats such as path and wall edges. It can act as a nutrient indicator because it often grows in alkaline and eutrophic to highly eutrophic soil. Other habitats include

loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–si ...

, boulders, concrete, exposed tree roots, soil covered logs and in the gaps between sidewalk stones. ''L. cruciata'' also grows as a horticultural weed in gardens, greenhouses and parks. ''L. cruciata'' is sensitive to frost, and is often found near water, where its gemmae are washed ashore.

Chemical properties

Like many other liverwort species, ''L. cruciata'' produces a dihydrostilbenoid growth hormone, lunularic acid, that is reported to be a growth inhibitor of liverworts.

Cadmium Cadmium is a chemical element; it has chemical symbol, symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12 element, group 12, zinc and mercury (element), mercury. Like z ...

in this liverwort also inhibits gemma germination and apical thallus growth, as well as altering cell and

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

structure.

Acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

extracts from ''L. cruciata'' were tested and showed antibacterial properties, but had no effects against fungal activity.

References

External links

Photos

{{Taxonbar, from1=Q1474234, from2=Q21441194, from3=Q17276679, from4=Q17276680 Liverworts Monotypic bryophyte genera Bryophyta of North America Flora of Africa Flora of Asia Flora of Australasia Flora of Europe Liverwort genera Plants described in 1753