''Acaena'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of about 60 species of mainly

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

, creeping

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition o ...

perennial plants and subshrubs in the family

Rosaceae Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are '' Alchemilla'' (270), ''Sorb ...

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a few species extending into the Northern Hemisphere, north to Hawaii ('' A. exigua'') and California ('' A. pinnatifida''). The

leaves 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 ...

are alternate, long, and pinnate or nearly so, with 7–21 leaflets. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanis ...

s are produced in a tight globose nflorescence in diameter, with no petals. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

is also a dense ball of many

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s; in many (but not all) species the seeds bear a barbed arrowhead point, the seedhead forming a burr which attaches itself to animal fur or feathers for dispersal. Several ''Acaena'' species in New Zealand are known by the common name bidibid. The word is written variously ''bidi-bidi'', ''biddy-biddy'', ''biddi-biddi'', ''biddi-bid'' and a number of other variations. These names are the English rendition of the original Māori name of ''piripiri''. The plant is also called the New Zealand burr. The species '' Acaena microphylla'' has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

Etymology

The generic name ''Acaena'' is derived from the Greek "akaina" (thorn), referring to the spiny

hypanthium In angiosperms, a hypanthium or floral cup is a structure where basal portions of the calyx, the corolla, and the stamens form a cup-shaped tube. It is sometimes called a floral tube, a term that is also used for corolla tube and calyx tube. It ...

Species

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

accepted the following species: *'' Acaena agnipila'' *'' Acaena alpina'' *'' Acaena anserinifolia'' *'' Acaena antarctica'' *'' Acaena argentea'' *'' Acaena boliviana'' *'' Acaena buchananii'' *'' Acaena caesiiglauca'' – glaucous pirri-pirri-bur *'' Acaena caespitosa'' *'' Acaena confertissima'' *''

Acaena cylindristachya ''Acaena'' is a genus of about 60 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a f ...

'' *'' Acaena dumicola'' (

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

of New Zealand) *'' Acaena echinata'' – sheep's burr *'' Acaena elongata'' *'' Acaena emittens'' (

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-larges ...

of New Zealand) *'' Acaena eupatoria'' *'' Acaena exigua'' – ''liliwai'' (

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

) *'' Acaena fissistipula'' *''

Acaena fuscescens ''Acaena'' is a genus of about 60 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a ...

'' *'' Acaena glabra'' *'' Acaena hirsutula'' *'' Acaena inermis'' *'' Acaena integerrima'' *'' Acaena juvenca'' (New Zealand) *'' Acaena latebrosa'' *'' Acaena leptacantha'' *'' Acaena longiscapa'' *''

Acaena lucida ''Acaena lucida'' is a small plant in the Rosaceae family, which is native to southern Chile, southern Argentina and the Falkland Islands. Taxonomy and naming ''Acaena lucida'' was first formally described in 1789 by William Aiton, as ''Ancis ...

'' *'' Acaena macrocephala'' *''

Acaena magellanica ''Acaena magellanica'', commonly called buzzy burr or greater burnet, is a species of flowering plant whose range includes the southern tip of South America and many subantarctic islands. Description ''Acaena magellanica'' is a perennial, mat- ...

'' – greater burnet *'' Acaena masafuerana'' *'' Acaena microphylla'' – New Zealand-bur *''

Acaena minor ''Acaena minor'' is a species of flowering plant whose range is confined to Australia's subantarctic Macquarie Island and to New Zealand's Campbell and Auckland Islands in the Southern Ocean. Description ''Acaena minor'' is a prostrate her ...

'' *'' Acaena montana'' *'' Acaena myriophylla'' *'' Acaena novae-zelandiae'' – red bidibid (New Zealand) *'' Acaena ovalifolia'' *''

Acaena ovina ''Acaena'' is a genus of about 60 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a ...

'' *''

Acaena pallida ''Acaena'' is a genus of about 60 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a ...

'' – sand bidibid *'' Acaena patagonica'' *'' Acaena pinnatifida'' – Argentinian biddy-biddy *'' Acaena platyacantha'' *'' Acaena poeppigiana'' *'' Acaena profundeincisa'' *'' Acaena pumila'' *'' Acaena rorida'' (North Island) *''

Acaena saccaticupula ''Acaena'' is a genus of about 60 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a ...

'' *'' Acaena sarmentosa'' *''

Acaena sericea ''Acaena sericea'' is a species of low growing perennial plant native to southern Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the cl ...

'' *'' Acaena splendens'' *'' Acaena stangii'' *'' Acaena stricta'' *''

Acaena subincisa ''Acaena'' is a genus of about 60 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a ...

'' *'' Acaena tenera'' – lesser burnet *'' Acaena tesca'' (South Island) *'' Acaena torilicarpa'' *'' Acaena trifida''

Invasive species

Some species have been introduced accidentally to other areas, attached to

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...

wool Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool. ...

, and have become

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...

. '' Acaena novae-zelandiae'', one of the bidibids from New Zealand, is the most commonly encountered species in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...

, where it is often abundant on coastal sand dunes, crowding out native vegetation and creating an often painful nuisance with the barbed burrs. In California, '' A. pallida'', ''A. novae-zelandiae'' and '' A. anserinifolia'' are considered serious weeds."Weeds Sorted by Pest Rating"
CFDA.ca.gov

References

External links

Jepson Manual TreatmentUSDA Plants ProfileLandcare Research New Zealand
{{Taxonbar, from=Q1327017 Pantropical flora Rosaceae genera