Click on images to enlarge
infestation (Photo: Forest and Kim Starr, USGS)
habit (Photo: Sheldon Navie)
habit of young plants (Photo: Sheldon Navie)
roots and stem bases (Photo: Sheldon Navie)
stems (Photo: Sheldon Navie)
close-up of stem showing thorns (Photo: Sheldon Navie)
immature and mature fruit (Photo: Jackie Miles and Max Campbell)
close-up of mature fruit (Photo: Sheldon Navie)
branches with fern-like 'leaves' (Photo: Sheldon Navie)
the numerous very fine 'leaves' (Photo: Sheldon Navie)
close-up of the needle-like 'leaves', which are borne in clusters along the branches (Photo: Sheldon Navie)
close-up of mature fruit (Photo: Sheldon Navie)
close-up of seeds (Photo: Tracey Slotta at USDA PLANTS Database)
comparison of the 'leaves' of Asparagus plumosus, on the left, and Aspargaus africanus, on the right (Photo: Sheldon Navie)
native asparagus fern (Asparagus racemosus) also has a climbing habit (Photo: Sheldon Navie)
the somewhat larger and flattened 'leaves' of Asparagus racemosus (Photo: Sheldon Navie)
Scientific Name
Asparagus plumosus Baker
Synonyms
Asparagus comorensis hort.Asparagopsis setacea KunthAsparagus setaceus (Kunth) JessopProtasparagus plumosus (Baker) Oberm.
Family
Asparagaceae (Queensland, New South Wales, the ACT and Western Australia)Liliaceae (Victoria, Tasmania, South Australia and the Northern Territory)
Common Names
asparagus fern, climbing asparagus, climbing asparagus fern, common asparagus fern, feathered asparagus fern, ferny asparagus, fern-asparagus
Origin
Native to southern and eastern Africa (i.e. Kenya, Zambia and South Africa).
Cultivation
Climbing asparagus fern (Asparagus plumosus) has been widely cultivated as a garden plant, particularly in southern and eastern Australia.
Naturalised Distribution
A relatively widespread species that is mostly found in the coastal regions of southern and eastern Australia. It is most common near the major urban areas in south-eastern Queensland (i.e. Brisbane), New South Wales (i.e. Sydney) and South Australia (i.e. Adelaide). It is also naturalised in other parts of New South Wales, in south-western Western Australia, in southern Victoria, in central Queensland, and on Lord Howe Island and Norfolk Island. There are also unconfirmed reports that it is naturalised near Cairns in northern Queensland.
Also naturalised in other parts of the world, including southern USA (i.e. in California and Florida), Puerto Rico, and some Pacific Islands (e.g. Hawaii and Tonga).
Habitat
A weed of tropical, sub-tropical and warmer temperate regions that is mostly found in rainforests, forest margins, urban bushland and wetter open woodlands. It is also commonly found growing along roadsides, in disturbed sites, and in parks and gardens.
Habit
A long-lived (i.e. perennial) climber with stems up to 5 m or more long.
Distinguishing Features
- a long-lived climber with stems that grow in a twining fashion.
- its stems produce short, horizontal-spreading, ferny branches bearing many tiny needle-like 'leaves'.
- these tiny, needle-like, 'leaves' (4-7 mm long and about 0.5 mm wide) are borne in clusters.
- its small white or greenish-white flowers are borne singly or in pairs along the branches.
- its fruit are small rounded berries (4-5 mm across) that turn black as they mature.
Stems and Leaves
The long-lived (i.e. perennial) stems are green to reddish brown in colour, hairless (i.e. glabrous), and either spineless or with some scattered spines. These stems grow in a twining fashion and produce numerous short, horizontal-spreading (i.e. lateral), branches.
The short, horizontal-spreading, (i.e. lateral), branches bear numerous tiny 'leaves' that give the plant a ferny appearance. The actual leaves are reduced to tiny scales and what appear to be the 'leaves' are actually small stems which look like and function as leaves (i.e. cladodes). Several of these hairless (i.e. glabrous) needle-like 'leaves' (4-7 mm long and about 0.5 mm wide) are produced in a cluster above each scale leaf.
Flowers and Fruit
The flowers are produced singly or in pairs in the forks (i.e. axils) of the scale leaves along the short lateral branches. They have three greenish-white sepals and petals (3-4 mm long), that are hard to distinguish from each other (i.e. six tepals or perianth segments), and six yellow stamens. Flowers are produced from spring through to early autumn.
The fruit are small rounded (i.e. globular) berries (4-5 mm across) and are initially green in colour. These berries turn black or bluish-black as they mature and contain one to three seeds (2.5-3.5 mm across) that are also black in colour.
Reproduction and Dispersal
This plant reproduces mainly by seed. Its berries are readily eaten and dispersed by fruit-eating (i.e. frugivorous) birds and other animals. Seeds may also be spread in dumped garden waste.
Environmental Impact
This species is regarded as an environmental weed in New South Wales and Queensland and was recently listed as a priority environmental weed in three Natural Resource Management regions. It is ranked among the top 100 most invasive weeds in south-eastern Queensland, where it is of particular concern in dry rainforests, and is actively managed by community groups in this region. Climbing asparagus fern (Asparagus plumosus) also appears on numerous regional environmental weed lists in New South Wales (e.g. on the Bushland Friendly Nursery Scheme environmental weeds list for north-eastern New South Wales and the environmental weed list for the wider Sydney and Blue Mountains region) and was recently ranked among the top twenty environmental weeds during a survey conducted in the North Coast region of this state.
In New South Wales it is extensively naturalised in coastal districts north from Royal National Park and it is often a serious weed in native bushland, coastal environs and rainforest communities. Once established it is difficult to eradicate and it is one of the species that has led to "the invasion and establishment of exotic vines and scramblers" being listed as a "key threatening process" in New South Wales. It is also one of a handful of exotic weeds that have the potential to significantly alter the habitat of the endangered Lord Howe woodhen (Gallirallus sylvestris), as it is a major weed of rainforests on Lowe Howe Island.
Legislation
This species is declared under legislation in the following states and territories:
- New South Wales: Class 4 - a locally controlled weed. The growth and spread of this species must be controlled according to the measures specified in a management plan published by the local control authority and the plant may not be sold, propagated or knowingly distributed (in the Hunters Hill, Hornsby, Ku-ring-gai, Lane cove, Lord Howe Island, Manly, Mosman, North Sydney, Parramatta, Pittwater, Ryde, Warringah and Willoughby local authority areas).
- Queensland: Class 3 - this species is primarily an environmental weed and a pest control notice may be issued for land that is, or is adjacent to, an environmentally significant area (throughout the entire state). It is also illegal to sell a declared plant or its seed in this state.
- Western Australia: Prohibited - on the prohibited species list and not permitted entry into the state.
Management
For information on the management of this species see the following resource:
- Muyt (2001), Bush Invaders of South-east Australia, pp. 123-125.
Similar Species
Climbing asparagus fern (Asparagus plumosus) is very similar to another species known as climbing asparagus fern (Asparagus africanus) and similar to ground asparagus fern (Asparagus aethiopicus 'Sprengeri'), bridal veil (Asparagus declinatus), bridal creeper (Asparagus asparagoides), garden asparagus (Asparagus officinalis), sicklethorn (Asparagus falcatus), Ming asparagus fern (Aspargaus retrofractus) and other asparagus ferns (Asparagus scandens and Asparagus virgatus). These species can be distinguished by the following differences:
- climbing asparagus fern (Asparagus plumosus ) is a climbing plant with long-lived and thornless or slightly thorny main stems. Its 'leaves' (i.e. cladodes) are borne in groups of more than three along the stems, are linear in shape, and are very small (4-7 mm long and only about 0.5 mm wide). Its flowers are borne singly or in pairs and its fruit turn black when mature.
- climbing asparagus fern (Asparagus africanus) is a climbing plant with long-lived and thorny main stems. Its 'leaves' (i.e. cladodes) are borne in groups of more than three along the stems, are linear in shape, and are relatively small (6-15 mm long and only about 0.5 mm wide). Its flowers are borne in small several-flowered clusters and its fruit turn orange when mature.
- ground asparagus fern (Asparagus aethiopicus 'Sprengeri') is usually a low-growing or scrambling plant with spreading or drooping branches bearing some small sharp thorns. Its 'leaves' (i.e. cladodes) are borne in groups of one to eight (usually 2-5) along the stems, are linear in shape, and are moderately large (15-25 mm long and 2-3 mm wide). Its flowers are borne in elongated, many-flowered clusters (i.e. racemes) and its fruit turn red when mature.
- bridal veil (Asparagus declinatus) is a creeping or climbing plant with short-lived thornless stems that die back each summer. Its 'leaves' (i.e. cladodes) are borne in groups of three along the stems, are linear in shape, and are relatively small (5-20 mm long and 0.5-1.5 mm wide). Its flowers are borne singly and its fruit turn bluish-grey or whitish in colour when mature.
- bridal creeper (Asparagus asparagoides) is a creeping or climbing plant with short-lived thornless stems that die back each summer. Its 'leaves' (i.e. cladodes) are borne singly along the stems, are oval (i.e. elliptic) in shape, and are relatively large (10-70 mm long and 10-30 mm wide). Its flowers are borne singly or in few-flowered clusters and its fruit turn red when mature.
- garden asparagus (Asparagus officinalis) is an upright plant (up to 2 m tall) with short-lived thornless stems that die back each summer. Its 'leaves' (i.e. cladodes) are borne in groups of one to five along the stems, are linear in shape, and are relatively small (12-25 mm long and 0.5 mm wide). Its flowers are borne singly or in pairs and its fruit turn red when mature.
- sicklethorn (Asparagus falcatus) is a shrubby climbing plant with long-lived and thorny main stems. Its 'leaves' (i.e. cladodes) are borne in groups of three to six along the stems, are elongated in shape, and are quite large (35-125 mm long and 2-5 mm wide). Its flowers are borne in elongated, many-flowered clusters (i.e. racemes) and its fruit turn red or whitish when mature.
- Ming asparagus fern (Aspargaus retrofractus) is shrubby plant with somewhat woody branches bearing some small sharp thorns. Its 'leaves' (i.e. cladodes) are borne in large clusters along the stems, are linear in shape, and are moderately large (12-25 mm long and only about 0.5 mm wide). Its flowers are borne in large rounded clusters and its fruit turn black when mature.
- asparagus fern (Asparagus scandens) is a creeping or climbing plant with short-lived or long-lived thornless stems. Its 'leaves' (i.e. cladodes) are borne in groups of three along the stems, are linear in shape (often slightly curved), and are relatively small (5-15 mm long and 0.5-1.5 mm wide). Its flowers are borne singly or in few-flowered clusters and its fruit turn orange or red when mature.
- asparagus fern (Asparagus virgatus) is an upright plant (up to 1.5 m tall) with short-lived or long-lived thornless stems. Its 'leaves' (i.e. cladodes) are borne in groups of three along the stems, are linear in shape, and are relatively small (6-20 mm long and 0.5-1 mm wide). Its flowers are borne singly and its fruit turn orange when mature.
It is also similar to the native asparagus fern (Asparagus racemosus) which is only found in northern Australia. These two species can be distinguished by the following differences:
- climbing asparagus fern (Asparagus plumosus) has 'leaves' (i.e. cladodes) that are linear in shape and very small (4-7 mm long and about 0.5 mm wide). Its flowers are borne singly or in pairs and its fruit (4-5 mm across) turn black when mature.
- native asparagus fern (Asparagus racemosus) has 'leaves' (i.e. cladodes) that are linear in shape and relatively large (10-30 mm long and less than 1 mm wide). Its flowers are borne in elongated, many-flowered clusters (i.e. racemes) and its fruit (3-4 mm across) turn red when mature.
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