Genus of flowering plants
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 species extending into the Northern Hemisphere, north to Hawaii (
A. exigua
) and California (
A. pinnatifida
).
[2]
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
bidi-bidi
,
biddy-biddy
,
biddi-biddi
,
biddi-bid
and a number of other variations. These names are the English rendition of the original M?ori name of
piripiri
.
[3]
The plant is also called the New Zealand burr. The species
Acaena microphylla
has gained the
Royal Horticultural Society
's
Award of Garden Merit
.
[4]
Etymology
[
edit
]
The generic name
Acaena
is derived from the Greek "akaina" (thorn), referring to the spiny
hypanthium
.
[5]
Species
[
edit
]
As of 2020
[update]
,
Plants of the World Online
accepted the following species:
[6]
Invasive species
[
edit
]
Some species have been introduced accidentally to other areas, attached to
sheep
's
wool
, and have become
invasive species
.
Acaena 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
,
A. novae-zelandiae
and
A. anserinifolia
are considered serious weeds.
[7]
References
[
edit
]
External links
[
edit
]
Wikimedia Commons has media related to
Acaena
.