''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 n ...

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, which ...

, 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 ...

perennial plants A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

and

subshrub A subshrub ( Latin ''suffrutex'') or dwarf shrub is a short shrub, and is a woody plant. Prostrate shrub is a related term. "Subshrub" is often used interchangeably with "bush".Jackson, Benjamin, Daydon; A Glossary of Botanic Terms with their ...

s 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), '' Sorbu ...

, native 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 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 mechanism ...

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 Burr may refer to: Places * Burr (crater), on the Jovian moon Callisto *Burr, Minnesota, an unincorporated community, United States * Burr, Missouri, an unincorporated community, United States *Burr, Nebraska, a village, United States * Burr, Sa ...

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 (No ...

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 ...

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'' 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 confertissima ''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 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 ''Acaena dumicola'' is a species of perennial plant found only in scrubby and rocky habitats at altitudes of between 300 and 1200 m in the South Island of New Zealand. This is a low plant distinctive for its prostrate branches each ending in th ...

'' (

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 Tasma ...

of New Zealand) *''

Acaena echinata ''Acaena echinata'', commonly known as sheep's burr, is a species of perennial herb, in the Rosaceae family, native to Australia. Description It grows to a height of 25–40 cm and has shiny, green fern-like leaves 60–150 mm long ...

'' – sheep's burr *'' Acaena elongata'' *''

Acaena emittens ''Acaena emittens'' is a species of perennial plant limited to scrubland and forest clearings at an altitude of 450–1500 m in central North Island, New Zealand. This plant has slender dark brown branches, growing prostrately, up to 50 cm ...

'' (

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'' 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 few ...

'' *'' 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 ...

) *''

Acaena fissistipula ''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 fuscescens ''Acaena'' is a genus of about 60 species of mainly evergreen, prostrate shrub, creeping herbaceous plant, herbaceous perennial plants and subshrubs in the family Rosaceae, native plant, native mainly to the Southern Hemisphere, notably New Zeala ...

'' *''

Acaena glabra ''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 hirsutula ''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 few ...

'' *''

Acaena inermis ''Acaena inermis'', the spineless acaena, is a species of flowering plant 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 ...

'' *''

Acaena integerrima ''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 few ...

'' *''

Acaena juvenca ''Acaena juvenca'' is a species of perennial plant found in scrubland and forest margins up to an altitude of 1200 m on the eastern side of both North and South Islands, New Zealand. This plant has slender reddish brown branches, often growing ...

'' (New Zealand) *''

Acaena latebrosa ''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 leptacantha ''Acaena'' is a genus of about 60 species of mainly evergreen, prostrate shrub, creeping herbaceous plant, herbaceous perennial plants and subshrubs in the family Rosaceae, native plant, native mainly to the Southern Hemisphere, notably New Zeala ...

'' *''

Acaena longiscapa ''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 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 ''Ancist ...

'' *''

Acaena macrocephala ''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 few ...

'' *'' Acaena magellanica'' – greater burnet *''

Acaena masafuerana ''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 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 herb. ...

'' *''

Acaena montana ''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 few ...

'' *''

Acaena myriophylla ''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 novae-zelandiae ''Acaena novae-zelandiae'', commonly known as red bidibid, bidgee widgee, buzzy and piri-piri bur, is a small herbaceous, prostrate perennial, native to New Zealand, Australia and New Guinea, of the family Rosaceae. Description ''Acaena ...

'' – red bidibid (New Zealand) *''

Acaena ovalifolia ''Acaena ovalifolia'' is a species of flowering plant belonging to the family Rosaceae. Its native range is Western South America to Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South ...

'' *''

Acaena ovina ''Acaena'' is a genus of about 60 species of mainly evergreen, prostrate shrub, creeping herbaceous plant, herbaceous perennial plants and subshrubs in the family Rosaceae, native plant, native mainly to the Southern Hemisphere, notably New Zeala ...

'' *''

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 f ...

'' – sand bidibid *''

Acaena patagonica ''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 few ...

'' *'' Acaena pinnatifida'' – Argentinian biddy-biddy *''

Acaena platyacantha ''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 poeppigiana ''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 profundeincisa ''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 pumila ''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 few ...

'' *''

Acaena rorida ''Acaena rorida'' is a species of mat-forming perennial plant known only from grassy uplands on the Mangaohane Plateau in the northwestern part of the Ruahine Range in the North Island of New Zealand. Within its range, this plant occurs in are ...

'' (North Island) *''

Acaena saccaticupula ''Acaena'' is a genus of about 60 species of mainly evergreen, prostrate shrub, creeping herbaceous plant, herbaceous perennial plants and subshrubs in the family Rosaceae, native plant, native mainly to the Southern Hemisphere, notably New Zeala ...

'' *''

Acaena sarmentosa ''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 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 clo ...

'' *''

Acaena splendens ''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 stangii ''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 few ...

'' *''

Acaena stricta ''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 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 f ...

'' *''

Acaena tenera ''Acaena tenera'', the lesser burnet, is a plant in the rose family Rosaceae. It is native to Patagonia and some subantarctic islands. Description ''Acaena tenera'' grows as a shrub-like herb. The species is similar to the greater burnet (''Acae ...

'' – lesser burnet *''

Acaena tesca ''Acaena tesca'' is a species of low growing perennial plant restricted to the upper slopes of the mountains of central Otago and northern Southland in the South Island of New Zealand. This plant spreads using subterranean stems and forms ma ...

'' (South Island) *''

Acaena torilicarpa ''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 trifida ''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 ...

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 domesticated sh ...

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 ...

. ''

'', 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 European mainland, continental mainland. It comprises England, Scotlan ...

, 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