''Asarum'' is a genus of plants in the birthwort family Aristolochiaceae, commonly known as wild ginger. ''Asarum'' is the genitive plural of the Latin ''āsa'' (an alternate form of ''āra'') meaning altar or sanctuary.

Description

''Asarum'' is a genus of low-growing herbs distributed across the temperate zones of the Northern Hemisphere, with most species in East Asia (China, Japan, and Vietnam) and North America, and one species in Europe. Biogeographically, ''Asarum'' originated in Asia. They have characteristic kidney-shaped leaves, growing from creeping rhizomes, and bear small,

axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

lary, brown or reddish flowers. The plant is called wild ginger because the rhizome tastes and smells similar to

ginger Ginger (''Zingiber officinale'') is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice A spice is a seed, fruit, root, bark, or other plant substance primarily used for flavoring or coloring food. Spices ...

root, but the two are not particularly related. The FDA warns against consuming ''Asarum'', as it is nephrotoxic and contains the potent carcinogen

aristolochic acid Aristolochic acids () are a family of carcinogenic, mutagenic, and nephrotoxic phytochemicals commonly found in the flowering plant family Aristolochiaceae (birthworts). Aristolochic acid (AA) I is the most abundant one. The family Aristolochiacea ...

. The birthwort family also contains the genus ''

Aristolochia ''Aristolochia'' () is a large plant genus with over 500 species that is the type genus of the family Aristolochiaceae. Its members are commonly known as birthwort, pipevine or Dutchman's pipe and are widespread and occur in the most diverse clima ...

'', known for carcinogens. Wild ginger favors moist, shaded sites with

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

-rich soil. The deciduous, heart-shaped

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are opposite, and borne from the rhizome which lies just under the soil surface. Two leaves emerge each year from the growing tip. The curious jug-shaped flowers, which give the plant an alternate name, little jug, are borne singly in spring between the leaf bases. Wild ginger can easily be grown in a shade garden, and makes an attractive

groundcover Groundcover or ground cover is any plant that grows over an area of ground. Groundcover provides protection of the topsoil from erosion and drought. In an ecosystem, the ground cover forms the layer of vegetation below the shrub layer known as t ...

Taxonomy

Traditionally, the genus ''Asarum'' was considered as a single genus with about 85 species. However, a trend exists among some botanists to segregate the genus into separate genera, based on considerations of chromosome number and floral morphology: * ''Asarum'' ''sensu stricto'' (about 17 species), distributed in Asia (mainly China), North America, and Europe * ''

Heterotropa ''Heterotropa'' is a monotypic moth genus in the subfamily Arctiinae. Its single species, ''Heterotropa fastosa'', is found in Australia's Northern Territory and Queensland. Both the genus and species were first described by Turner in 1940. ...

'' (about 50 species), distributed in Asia * '' Asiasarum'' (three or four species), distributed in Asia * '' Geotaenium'' (three or four species), distributed in Asia * '' Hexastylis'' (ten species), distributed in North America Study of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA, combined with morphological data, has yielded a better-resolved phylogenetic hypothesis, supporting a recognition of two subgenera, ''Asarum'' and ''Heterotropa'' each containing two sections, rather than the segregated genera above. *''Asarum'' ''sensu stricto'' (''s.s.'') : the North American species are

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

and are derived from within the

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

Asian species group. * ''Geotaenium'' is a sister to ''Asarum'' ''s.s.'', showing its close relationship to ''Asarum'' ''s.s.''. * ''Asiasarum'' is a sister to the ''Hexastylis'' + ''Heterotropa'' clade, showing several

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

with this clade. * ''Hexastylis'': this genus has been recognized solely on the study by H.L. Blomquist. However, the above-mentioned DNA study provided indications that ''Hexastylis'' is not monophyletic and that some species of ''Hexastylis'' are more closely related to Asiatic species of ''Heterotropa'' than they are to other species of ''Hexastylis''. * ''Heterotropa'': this is a complex monophyletic group, well nested within the ''Asiasarum'' + ''Hexastylis'' + ''Heterotropa'' clade Therefore, many botanists still treat these segregated genera as subgenera and sections of ''Asarum'' ''sensu lato'', especially ''Hexastylis''.

Species

Uses

Wild ginger can be cooked in the same fashion as ginger root, and can also be candied or used to make medicine.

References

External links

* *
List of ''Asarum'' speciesThe International Agency for Research on Cancer
{{Taxonbar, from=Q157718 Piperales genera Herbs