''Centipeda'' is a genus of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the daisy family,

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

. The genus is primarily native to

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 ...

and

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 ...

, with a few species extending the range northward into Asia and across the Pacific to southern

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Species

Research and biological activities

Volatile oils An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

from '' Centipeda minima'' have been shown to modulate

anti-inflammatory Anti-inflammatory is the property of a substance or treatment that reduces inflammation, fever or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs reduce pain by inhibiting mechan ...

action by inhibiting inflammatory

cytokine Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...

s in a rat model. In a related study, ''C. minima'' eased

allergic rhinitis Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. It is classified as a type I hypersensitivity reaction. Signs a ...

by slowing the infiltration of

eosinophil Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. Along wi ...

s and the proliferation of

mast cell A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a p ...

s. A comprehensive investigation of the GC-MS chemical profile of '' C. cunninghamii'' and its biological activity showed that this species' extract contains novel compounds that possess anti-inflammatory and antioxidant properties.

Phylogeny

In 2012, Nylinder et al. published an estimation of the species tree

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

of the Australian/New Zealand genus ''Centipeda'' (

) based on nucleotide sequence data. ''Centipeda racemosa'' (snuffweed) is the sister to remaining species, which is also the only consistently perennial representative in the genus. ''Centipeda pleiocephala'' (tall sneezeweed) and ''C. nidiformis'' (cotton sneezeweed) constitute a species pair, as does ''C. borealis'' and ''C. minima'' (spreading sneezeweed), all sharing the symplesiomorphic characters of spherical capitulum and convex receptacle with ''C. racemosa''. Another species group comprising ''C. thespidioides'' (desert sneezeweed), Centipeda cunninghamii (old man weed, or common sneezeweed), ''C. crateriformis'' is well supported but then include the morphologically aberrant ''C. aotearoana'', all sharing the character of having capitula that mature more slowly relative the subtending shoot. ''Centipeda elatinoides'' takes on a weakly supported intermediate position between the two mentioned groups, and is difficult to relate to any of the former groups based on morphological characters.

References

{{Taxonbar, from=Q2698575 Asteraceae genera Athroismeae Plants used in traditional Chinese medicine Taxa named by João de Loureiro