Citrus australasica

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Australian finger lime
Citrus australasica green fruit1.JPG
Green skin type finger lime
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Rutaceae
Genus: Citrus
Species:
C. australasica
Binomial name
Citrus australasica
Synonyms [1]

Citrus australasica, the Australian finger lime or caviar lime, is a thorny understorey shrub or small tree of lowland subtropical rainforest and rainforest in the coastal border region of Queensland and New South Wales, Australia.

Contents

It has edible fruits which are under development as a commercially sold crop. [2] [3]

Description

The plant is 2–7 m (6 ft 7 in – 23 ft 0 in) in height. The leaves are small, 1–6 cm (0.39–2.36 in) long and 3–25 mm (0.12–0.98 in) wide, glabrous, with a notched tip and crenate towards the apex. Flowers are white with petals 6–9 mm (0.24–0.35 in) long. The fruit is cylindrical, 4–8 cm (1.6–3.1 in) long, sometimes slightly curved, coming in different colours, including pink and green. [2]

Cultivation and uses

History

Early settlers consumed the fruit [4] and retained the trees when clearing for agriculture. Colonial botanists suggested that they should be cultivated, due to the lack of citrus alternatives. [4]

Rising demand

Red finger lime with juice vesicles partially extracted Finger lime - juice vesicles - 01.jpg
Red finger lime with juice vesicles partially extracted

The finger lime has been recently[ when? ] popularised as a gourmet bushfood. The globular juice vesicles (also known as pearls) have been likened to a "lime caviar", [5] [6] which can be used as a garnish or added to various recipes. The fresh vesicles have the effect of a burst of effervescent tangy flavour as they are chewed. The fruit juice is acidic and similar to that of a lime. Marmalade and pickles are also made from finger lime. Finger lime peel can be dried and used as a flavouring spice. [2]

Commercial use of finger lime fruit started in the mid-1990s with boutique marmalades made from wild harvested fruit. By 2000 the finger lime was being sold in restaurants, and exported fresh. [2]

The finger lime has been recently[ when? ] grown on a commercial basis in Australia in response to high demand for the fruit. There is an increasing range of genetic selections which are budded onto citrus rootstock. With the sudden high market demand for the fruit the primary source of genetic material for propagation has been selections from wild stock.[ citation needed ]

Diseases

Two red finger limes, shown next to an Australian ten-cent coin (23 mm (0.91 in) diameter) Finger limes - size comparison.jpg
Two red finger limes, shown next to an Australian ten-cent coin (23 mm (0.91 in) diameter)

In cultivation, the finger lime plant is grown in much the same way as other citrus species. It may be subject to some pests and diseases requiring pest control in cropping situations. This includes scale, caterpillars, gall-wasp, and limb dieback. Fruit fly research has concluded that finger limes are a non-host plant to fruit flies and as such are not a quarantine risk to importing countries.

Research conducted since the 1970s indicated that a wild selection of C. australasica was highly resistant to Phytophthora citrophthora root disease, which has resulted in a cross-breeding program with finger lime to develop disease-resistant citrus rootstock. In 2020, researchers began working with C. australasica to develop solutions for Citrus greening disease. [4] [7]

The CSIRO has also developed several Citrus hybrids by crossing the finger lime with standard Citrus species. These hybrids have created many cultivars which generate finger limes in many different colors ranging from light pink to deep blue-green. Finger lime is thought to have the widest range of color variation within any Citrus species. The color of the pulp (juice vesicles) comes in shades of green or pink including pale lime-green, pale pink, coral, and scarlet.

Taxonomy

Historically the finger lime was viewed as a member of the genus Citrus. The Swingle system of taxonomy instead divided the historical true citrus into seven genera, placing the finger lime along with the round lime in a novel genus, Microcitrus . [1] However, subsequent studies have favored a broader concept of Citrus that reunites the genera separated by Swingle, restoring the finger lime to Citrus.

Australian limes
former  Eremocitrus

Citrus glauca

former  Microcitrus

Citrus warburgiana

Citrus inodora

Citrus maideniana

Citrus garrawayi

Citrus australasica

Citrus australis

[8]

Related Research Articles

<span class="mw-page-title-main">Kumquat</span> Species of small fruit-bearing tree

Kumquats, or cumquats in Australian English, are a group of small, angiosperm, fruit-bearing trees in the family Rutaceae. Their taxonomy is disputed. They were previously classified as forming the now-historical genus Fortunella or placed within Citrus, sensu lato. Different classifications have alternatively assigned them to anywhere from a single species, C. japonica, to numerous species representing each cultivar. Recent genomic analysis would define three pure species, Citrus hindsii, C. margarita and C. crassifolia, with C. x japonica being a hybrid of the last two.

<i>Citrus</i> Genus of flowering plants

Citrus is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus Citrus is native to South Asia, East Asia, Southeast Asia, Melanesia, and Australia. Various citrus species have been used and domesticated by indigenous cultures in these areas since ancient times. From there its cultivation spread into Micronesia and Polynesia by the Austronesian expansion ; and to the Middle East and the Mediterranean via the incense trade route, and onwards to Europe and the Americas.

<span class="mw-page-title-main">Calamansi</span> Hybrid species of citrus

Calamansi, also known as kalamansi, calamondin, Philippine lime, or Philippine lemon, is an economically important citrus hybrid predominantly cultivated in the Philippines. It is native to the Philippines, parts of Indonesia, Malaysia, and Brunei, as well as parts of southern China and Taiwan.

<span class="mw-page-title-main">Lime (fruit)</span> Citrus fruit

A lime is a citrus fruit, which is typically round, green in color, 3–6 centimetres (1.2–2.4 in) in diameter, and contains acidic juice vesicles.

<span class="mw-page-title-main">Australian lime</span> Lime cultivar

Australian limes are species of the plant genus Citrus that are native to Australia and Papua New Guinea.

<span class="mw-page-title-main">Pomelo</span> Citrus fruit from Southeast Asia

The pomelo, from the family Rutaceae, is the largest citrus fruit, and the principal ancestor of the grapefruit. It is a natural, non-hybrid, citrus fruit, native to Southeast Asia. Similar in taste to a sweet grapefruit, the pomelo is commonly consumed and used for festive occasions throughout Southeast Asia. As with the grapefruit, phytochemicals in the pomelo have the potential for drug interactions.

<span class="mw-page-title-main">Citrus production</span> Cultivation or planting of citrus fruits

Citrus production encompasses the production of citrus fruit, which are the highest-value fruit crop in terms of international trade. There are two main markets for citrus fruit:

<span class="mw-page-title-main">Trifoliate orange</span> Species of plant in the Rutaceae family

The trifoliate orange, Citrus trifoliata, is a member of the family Rutaceae. Whether the trifoliate oranges should be considered to belong to their own genus, Poncirus, or be included in the genus Citrus is debated. The species is unusual among citrus for having deciduous, compound leaves and pubescent (downy) fruit.

<span class="mw-page-title-main">Blood lime</span> Citrus fruit and plant

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<span class="mw-page-title-main">Key lime</span> Citrus fruit and plant

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<span class="mw-page-title-main">Orange (fruit)</span> Citrus fruit

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<i>Citrus glauca</i> Species of plant

Citrus glauca, commonly known as the desert lime, is a thorny shrub or small tree native to Queensland, New South Wales, and South Australia. The 1889 book The Useful Native Plants of Australia records common names native kumquat and desert lemon.

<i>Citrus australis</i> Species of shrub

Citrus australis, the Dooja, round lime, Australian lime or Australian round lime, is a large shrub or small tree producing an edible fruit. It grows in forest margins in the Beenleigh area and northwards, in Queensland, Australia.

<span class="mw-page-title-main">Papeda (citrus)</span> Citrus fruit and plant

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Citrus macroptera, also known as shatkora or hatkhoracabuyao, Melanesian papeda, or wild orange, is a semi-wild species of citrus native to the Sylhet region of Bangladesh.

Caviar, sometimes Kaviar is, primarily, the name given to the luxury delicacy consisting of processed, salted, non-fertilized sturgeon roe.

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<span class="mw-page-title-main">Citrus blight</span> Tree disease

Citrus blight is a type of blight that occurs in tropical and semi-tropical regions. Specializing in infecting citrus trees, the blight is found in North America, the Caribbean, South America, South Africa and Australia. The blight injures plants by forming blockages in xylem and phloem, inhibiting resource distribution and resulting in plant die-back and smaller fruit yields. As of 2020 there is no cure for the blight, and neither the causal agent nor spreading mechanism is known.

References

  1. 1 2 "Citrus australasica F.Muell. — The Plant List". www.theplantlist.org. Archived from the original on 2018-12-26. Retrieved 2014-04-10.
  2. 1 2 3 4 "Citrus pages, Native Australian Citrus, Citrus australasica". users.kymp.net. Archived from the original on 2021-12-22. Retrieved 2014-04-10.
  3. Mueller, Ferdinand von (April 2, 1858). Fragmenta phytographiæ Australiæ /. Vol. v.1 1858-59. Auctoritate Gubern. Coloniæ Victoriæ, Ex Officina Joannis Ferres. Archived from the original on November 1, 2022. Retrieved April 2, 2020.
  4. 1 2 3 Low, Tim, Wild Food Plants of Australia, ISBN   0207143838 [ page needed ]
  5. Karp, David (23 December 2009). "Finger lime: the caviar of citrus". Los Angeles Times. Archived from the original on 31 May 2015. Retrieved 1 June 2015 via LA Times.
  6. Star, Tamborine Mountain Daily. "Nature's 'Little Pearls', The Exotic Finger Lime". www.tamborine-daily-star.com. Archived from the original on 2018-06-25. Retrieved 2018-06-25.
  7. Allen, Greg (July 27, 2020). "Exotic Australian Fruit May Help Save Florida's Citrus Industry". NPR. Retrieved 28 July 2020.
  8. Jorma Koskinen and Sylvain Jousse. "Citrus Pages / Native Australian varieties". free.fr. Archived from the original on 2015-07-11. Retrieved 2016-08-11.