Download Abrus precatorius subsp. africanus

Weeds of Australia - Biosecurity Queensland Edition Fact Sheet
Abrus precatorius subsp. africanus
Scientific Name
Abrus precatorius subsp. africanus Verdc.
Synonyms
Abrus precatorius L.
infestation (Photo: Sheldon Navie)
Abrus precatorius L. subsp. precatorius (misapplied)
Family
Fabaceae (Queensland, the ACT, Victoria, Tasmania and the Northern Territory)
Fabaceae: subfamily Faboideae (New South Wales)
Leguminosae (South Austrlaia)
Papillionaceae (Western Australia)
Common Names
scrambling habit (Photo: Sheldon Navie)
bead vine, black-eyed Susan, coral bead plant, coral bean, crabs eye, crab's eye, crab's
eye creeper, crab's eye vine, crab's eyes, crab's-eye, crab's-eye creeper, crabs-eye
creeper, gidee -gidee, Indian licorice, jequirity, jecquirity bean, jequirity seeds, licorice
vine, love bean , lucky bean, prayer beads, prayer bean, precatory pea, red beadvine,
rosary bean, rosary pea, weatherplant, weathervine
Origin
Native to tropical Africa, Madagascar and some islands in the western Indian Ocean
(Mauritius and the Seychelles)
Cultivation
climbing habit (Photo: Sheldon Navie)
Crab's eye creeper ( Abrus precatorius subsp. africanus) has been widely cultivated as a
garden ornamental, largely because of its attractive and decorative bright red and black
coloured seeds.
Naturalised Distribution
The plant is becoming widely naturalised in south-eastern Queensland. It has also been
recorded from north-eastern New South Wales and the coastal districts of central
Queensland.
Habitat
stems and older leaves (Photo: Sheldon Navie)
A common weed of roadsides, old gardens, disturbed sites, waste areas and waterways
(i.e. riparian areas) in the higher rainfall areas of sub-tropical eastern Australia. It has
also been reported from open woodlands, rainforest margins and coastal fore-dunes in
this region.
In Hawaii it has become naturalised in dry disturbed sites, while in Florida it has invaded
undisturbed pine forests and other open woodlands.
Habit
A slender, but long-lived (i.e. perennial), climbing plant that grows up over supporting
vegetation adn can reach up to 10 m or more in height.
Distinguishing Features
a climbing plant with slender twining stems.
its once-compound leaves have several to numerous pairs of small leaflets.
its pea-shaped whitish, pink or purplish flowers (about 10 mm long) are
borne in dense, slightly elongated, clusters.
its relatively short pods (20-35 mm long) have a rough surface texture.
these pods split open when mature to reveal several bright red and black
coloured seeds (5-7 mm long).
close-up of younger leaves (Photo: Sheldon Navie)
Stems and Leaves
leaf undersides and twining growing tips (Photo: Sheldon
Navie)
Older stems are covered in a smooth-textured or wrinkled brown bark. Younger stems
are generally smooth, covered in tiny hairs (i.e. pubescent), and greenish in colour.
The alternately arranged leaves (5-13 cm long) are once-compound (i.e. pinnate) with 517 pairs of leaflets. These leaflets (5-25 mm long and 2-8 mm wide) are mostly hairless
(i.e. glabrous), oblong in shape, and have rounded tips (i.e. obtuse apices).
Flowers and Fruit
The small whitish, pink, mauve or purplish pea-shaped flowers (about 10 mm long) are
borne in dense slightly elongated clusters. These flower clusters are usually arranged
on stalks (i.e. peduncles) that emanate from the leaf forks (i.e. axillary racemes).
Individual flowers have five small green sepals, which are fused together at the base
into a short tube (i.e. calyx tube). They have a large upper petal (i.e. standard), two side
petals (i.e. wings) and two lower petals that are fused together and folded lengthwise
(i.e. a keel).
flower clusters with a couple of young fruit beginning to
develop (Photo: Sheldon Navie)
The fruit is a flat and realtively broad pod (20-35 mm long and 12-15 mm wide) with a
sharp point (i.e. beak). These pods are sparsely covered in hairs and have a rough
texture (i.e. they are tuberculate). When mature, these brown pods split open and curl
back to reveal several (usually 3-7) oval-shaped (i.e. ellipsoid) seeds. The very
distinctive seeds (5-7 mm long and 4-5 mm wide) are bright scarlet-red in colour with a
large black spot. They are smooth in texture, glossy in appearance and generally
remain on the plant for some time (i.e. several months).
Reproduction and Dispersal
close-up of the pea-shaped flowers (Photo: Sheldon Navie)
This species reproduces mainly by seed. These seeds are thought to be mostly birddispersed, but it is likely that they are also spread along waterways during floods and in
dumped garden waste.
Environmental Impact
Crab's eye creeper ( Abrus precatorius subsp. africanus) is regarded as an
environmental weed in New South Wales and south-eastern Queensland. It is currently
of most concern in north-eastern New South Wales, where it is a relatively recent
introduction, but it is much more common and widespread in south-eastern
Queensland.
This species has been reported in various types of open woodlands (e.g. banksia and
eucalypt forests) in the coastal districts of northern New South Wales. It appears on
the regional environmental weed list for north-eastern New South Wales, developed by
the Bushland Friendly Nursery Scheme, and hence also appears on several local
environmental weed lists in this region (e.g. in Ballina Shire, Lismore City and Coffs
Harbour City councils).
Crab's eye creeper ( Abrus precatorius subsp. africanus ) is also one of the "exotic vines
and scramblers" whose invasion of native plant communities is listed as a "key
threatening process" in New South Wales. Such species are of concern because they
may act as transformer species, altering the nature of the plant communities that they
invade. Exotic vines and scramblers smother existing vegetation, both in the ground
layer and canopy, altering the light climate and suppressing the regeneration of native
species.
close-up of immature fruit, with rough surfaces (Photo:
Sheldon Navie)
numerous clusters of mature fruit (Photo: Sheldon Navie)
Until recently, crab's eye creeper ( Abrus precatorius) was often regarded as being
native to south-eastern Queensland, or as being introduced here from northern
Queensland, and was not treated as a serious threat. However, now that it is known
to be an exotic form of this species, crab's eye creeper ( Abrus precatorius subsp.
africanus) is beginning to be treated with more concern as a potentially invasive plant.
Populations of this weed are becoming more common and widespread in the region,
and are often seen in riparian areas and revegetation sites in suburban Brisbane (e.g.
along Enoggera Creek in The Gap and the along the Brisbane River in St. Lucia).
Infestations are also being actively controlled on Fraser Island.
Crab's eye creeper ( Abrus precatorius) is also regarded as a serious invasive weed in
some parts of the USA, particularly throughout the central and southern parts of
Florida, where it is noted to establish well in disturbed drier forests and spread rapidly
after fires.
Other Impacts
The seeds of this species are extremely toxic to humans and livestock (e.g. cattle and
horses).
Legislation
densely clustered mature fruit with seeds (Photo: Sheldon
Navie)
This species is not declared or considered noxious by any State or Territory.
Similar Species
Because of its very distinctive seeds, crab's eye ( Abrus precatorius) is rarely confused
with other species. However, the introduced form of this species (i.e. Abrus precatorius
subsp. africanus) is extremely similar to the native form which grows in northern
Australia (i.e. Abrus precatorius subsp. precatorius). These two subspecies can be
distinguished by the following differences:
Abrus precatorius subsp. africanus has smaller pods (20-35 mm long) with a
rough surface texture (i.e. they are tuberculate).
Abrus precatorius subsp. precatorius has larger pods (30-50 mm long) with a
relatively smooth surface texture.
close-up showing the red-and-black seeds and rough
surface texture of the pods (Photo: Sheldon Navie)
Giddy giddy ( Adenanthera abrosperma), a native tree from northern Queensland, has
almost identical red and black seeds. However, this plant can be easily distinguished by
its arborescent habit, globular flower clusters, and twice-compound (i.e. bipinnate)
leaves.
Fact sheets are available from Department of Employment, Economic Development and Innovation
(DEEDI) service centres and our Customer Service Centre (telephone 13 25 23). Check our website
at www.biosecurity.qld.gov.au to ensure you have the latest version of this fact sheet. The control
methods referred to in this fact sheet should be used in accordance with the restrictions (federal
and state legislation, and local government laws) directly or indirectly related to each control method.
These restrictions may prevent the use of one or more of the methods referred to, depending on
individual circumstances. While every care is taken to ensure the accuracy of this information, DEEDI
does not invite reliance upon it, nor accept responsibility for any loss or damage caused by actions
based on it.
close-up of seeds (Photo: Steve Hurst at USDA PLANTS
Database)
Copyright © 2016. All rights reserved. Identic Pty Ltd. Special edition of Environmental Weeds of
Australia for Biosecurity Queensland.
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close-up of immature fruit of the native form of this
species, Abrus precatorius subsp. precatorius, with
smooth surfaces (Photo: Chris Gardiner)