Cladus: Eukaryota
Regnum: Plantae
Divisio: Magnoliophyta
Classis: Magnoliopsida
Ordo: Rosales
Familia: Rosaceae
Subfamilia: Rosoideae
Tribus: Sanguisorbeae
Subtribus: Sanguisorbinae
Genus: Acaena
Species: A. adscendens - A. agnipila - A. alpina - A. anserinifolia - A. antarctica - A. argentea - A. arvensis - A. boehmerioides - A. buchananii - A. buchanii - A. caesiiglauca - A. caespitosa - A. ciliata - A. cylindristachya - A. dumicola - A. echinata - A. elongata - A. eupatoria - A. exigua - A. fallax - A. fissistipula - A. glabra - A. hieronymi - A. hirsuta - A. hispida - A. indica - A. inermis - A. integerrima - A. laevigata - A. latebrosa - A. lucida - A. macrocephala - A. macrostachya - A. macrostemon - A. magellanica - A. microphylla - A. minor - A. myriophylla - A. neomexicana - A. novae-zelandica - A. ostryaefolia - A. ovalifolia - A. ovina - A. pallida - A. pinnatifida - A. platyacantha - A. poeppigiana - A. poiretti - A. profundeincisa - A. pumila - A. rhomboidea - A. saccaticupula - A. sanguisorbae - A. schiedeana - A. segetalis - A. sericea - A. setosa - A. splendens - A. tetragonioides - A. trifida - A. virginica - A. viridior - A. wilkesiana


Acaena Mutis ex L.

Vernacular names
Dansk: Tornnød
Deutsch: Stachelnüsschen


Acaena is a genus of about one hundred species of perennial herbs and subshrubs in the Rosaceae, 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 Hawaiʻi (A. exigua) and California (A. pinnatifida).

The leaves are alternate, 4–15 centimetres (1.6–5.9 in) long, and pinnate or nearly so, with 7-21 leaflets. The flowers are produced in a tight globose [inflorescence] 1–2 centimetres (0.39–0.79 in) in diameter, with no petals. The fruit is also a dense ball of many seeds; 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 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.[1]

Selected species

* Acaena adscendens
* Acaena anserinifolia
* Acaena argentea
* Acaena buchananii
* Acaena caesiiglauca
* Acaena dumicola Macmillan, 1985 (South Island of New Zealand)
* Acaena emittens Macmillan, 1989 (North Island of New Zealand)
* Acaena exigua A.Gray - Liliwai (Hawaiʻi)
* Acaena fissistipula
* Acaena glabra
* Acaena inermis
* Acaena juvenca Macmillan, 1989 (New Zealand)
* Acaena laevigata
* Acaena lucida
* Acaena magellanica
* Acaena microphylla
* Acaena myriophylla
* Acaena novae-zelandiae Kirk - Bidibid (New Zealand)
* Acaena ovalifolia
* Acaena ovina
* Acaena pallida (Kirk) Allen - Sand bidibid
* Acaena pinnatifida Ruiz & Pav. - Sheepburr
* Acaena platyacantha
* Acaena pumila
* Acaena rorida Macmillan, 1991 (North Island of New Zealand)
* Acaena saccaticupula
* Acaena sanguisorbae
* Acaena sericea
* Acaena splendens
* Acaena tesca Macmillan, 1991 (South Island of New Zealand)
* Acaena trifida

Invasive species

Some species have been introduced accidentally to other areas, attached to sheep's wool, and have become invasive species. A. novae-zelandiae, one of the bidibids from New Zealand, is the most commonly encountered species in the United Kingdom, 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, from New Zealand and southeast Australia, is similarly a problem species.


1. ^ Orsman, H. W. (1999). The Dictionary of New Zealand English. Auckland: Oxford University Press.

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Source: Wikispecies, Wikipedia: All text is available under the terms of the GNU Free Documentation License