| small-leaved fig | |
|---|---|
| Ficus obliqua, Allyn River, Barrington Tops | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Rosids |
| Order: | Rosales |
| Family: | Moraceae |
| Genus: | Ficus |
| Species: | F. obliqua |
| Binomial name | |
| Ficus obliqua G.Forst. |
|
| Synonyms | |
|
Ficus obliqua var. obliqua G.Forst. |
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Ficus obliqua, commonly known as the small-leaved fig, a tree in the family Moraceae native to eastern Australia. It is a banyan of the genus Ficus which contains around 750 species worldwide in warm climates, including the edible fig (Ficus carica). It is found along the east coast from Queensland, through New South Wales in rainforest, savanna woodland, sclerophyll forest and gallery forest. It can grow to 60 m (200 ft) high and nearly as wide. F. obliqua is pollinated by two species of fig wasp—Pleistodontes greenwoodi and P. xanthocephalus. Many species of bird, including pigeons, parrots and various passerines, consume the fruit. It is used as a shade tree in parks and public spaces, and is well-suited for use in bonsai.
Contents |
Commonly known as the small-leaved Fig, Ficus obliqua was described by German naturalist Georg Forster in 1786 with the type material collected in Vanuatu. Dutch botanist Friedrich Miquel described Urostigma eugenioides from Albany Island in Queensland in 1861, which was reclassified by Victorian State Botanist Ferdinand von Mueller as Ficus eugenioides in 1867, and it was known as this for many years, however Forster's name is older and thus has precedence. The specific epithet is the Latin adjective obliquus "oblique", although what attribute it refers to is unclear.[2]
The species is currently regarded as monotypic. Three varieties of Ficus obliqua were recognised until 2001—F. obliqua var. petiolaris, F. obliqua var. obliqua, and F. obliqua var. puberula from Western Australia. However, a revision of the group led to the conclusion that F. obliqua var. petiolaris actually belonged in the species F. rubiginosa.[3] F. obliqua var. puberula was found to be more distantly related to obliqua than rubiginosa and hence has been reclassified as a separate species, Ficus brachypoda.[4]
With over 750 species, Ficus is one of the largest angiosperm genera.[5] Based on morphology, English botanist E. J. H. Corner divided the genus into four subgenera;[6] later expanded to six.[7] In this classification, Ficus obliqua was placed in subseries Malvanthereae, series Malvanthereae, section Malvanthera of the subgenus Urostigma.[8] In his reclassification of the Australian Malvanthera, Australian botanist Dale J. Dixon altered the delimitations of the series within the section, but left this species in series Malvanthereae.[6]
In a study published in 2008, Nina Rønsted and colleagues analysed the DNA sequences from the nuclear ribosomal internal and external transcribed spacers (ITS and ETS), and the glyceraldehyde-3-phosphate dehydrogenase (G3pdh) region, in the first molecular analysis of the section Malvanthera. They found F. obliqua to be most closely related to three species of the arid Northern Territory (F. platypoda, F. subperula and F. lilliputiana) and classified it in a new series Obliquae in the subsection Platypodeae. The species had remained a transitional rainforest species while its relatives radiated into dryer habitat.[8]
Ficus obliqua is a tree which may reach 15–60 m (50–200 ft) in height and similar width.[9] It has smooth thin grey bark with lighter-colured lenticels, and a buttressed trunk, which may reach 3 m (10 ft) in diameter. The glossy green leaves are elliptic to oblong in shape and measure 5–8 cm (2–3 in) long by 2–3.5 cm (0.8–1.4 in) wide on 1–2 cm (0.4–0.8 in) petioles.[9] They are alternately arranged on the stems.[2] Growing in pairs, the round yellow fruit turns orange or orange-red dotted with darker red and reaches a diameter of 6 to 10 mm (0.2–0.4 in) upon ripening over April to July,[9] though fruit can appear at other times of year.[10]
Historically, there has been some confusion with the related Ficus rubiginosa,[4] however F. obliqua can be distinguished by its smaller fruit on shorter stalks, and its glabrous (hairless) leaves and the petioles have ascending hyaline hairs;[11] some forms of F. rubiginosa have both leaves and petioles glabrous while others have both covered in fine fur.[4] The synconia of F. obliqua are smaller, measuring 4.3–11.9 mm long and 4.4–11.0 mm in diameter, compared with 7.4–17.3 mm long and 7.6–17.3 mm diameter for F. rubiginosa'.'[4]
Ficus obliqua occurs from Mount Dromedary (36° S) in southern New South Wales northwards along the coast and Great Dividing Range to the tip of Cape York Peninsula in north Queensland and New Guinea and offshore islands,[11] as well as throughout the Pacific Islands.[4] It had been thought to occur in Western Australia, but these collections have been now referred to Ficus brachypoda.[4] Preferring high nutrient soils with high water content, it occurs on sandstone or latite soils in the Sydney region. The habitat is warm temperate to moist subtropical rainforest as well as littoral rainforest. Large specimens can rise above the canopy as emergent trees.[10]
The Double-eyed Fig-parrot (Cyclopsitta diophthalma) eats the fruit of Ficus obliqua, steadily depositing fruity detritus on the ground.[12] The Rainbow Lorikeet (Trichoglossus moluccanus) is another parrot which consumes the fruit and disperses the seeds;[3] other bird species include the Brown Cuckoo-Dove (Macropygia phasianella), Rose-crowned Fruit-dove (Ptilinopus regina), Wompoo Fruit-dove (P. magnificus), Wonga Pigeon (Leucosarcia melanoleuca), Topknot Pigeon (Lopholaimus antarcticus), Silvereye (Zosterops lateralis), Pied Currawong (Strepera graculina), Black-faced Cuckoo-shrike (Coracina novaehollandae), Olive-backed Oriole (Oriolus sagittatus), Australasian Figbird (Sphecotheres vieilloti), Green Catbird (Ailuroedus crassirostris), Regent Bowerbird (Sericulus chrysocephalus), Satin Bowerbird (Ptilonorhynchus violaceus), and Lewin's Honeyeater (Meliphaga lewinii).[2] The Spectacled Flying Fox (Pteropus conspicillatus)[13] and Grey-headed Flying Fox (Pteropus poliocephalus) eat the fruit.[10]
Leaves of Ficus obliqua serve as a food source for the larvae of the butterfly species the Common Crow (Euploea core),[14] the No-brand Crow (Euploea alcathoe),[15] and the geometer moth (Scopula epigypsa).[16]
The thrips species Gynaikothrips australis feeds on the underside of new leaves of F. obliqua, as well as F. rubiginosa and F. macrophylla. As plant cells die, nearby cells are induced into forming meristem tissue and a gall results, and the leaves become distorted and curl over. The thrips begin feeding when the tree has flushes of new growth, and the life cycle is around six weeks. At other times, thrips reside on old leaves without feeding. The species pupates sheltered in the bark. The thrips remain in the galls at night and wander about in the daytime and return in the evening, possibly to different galls about the tree.[17]
Figs have an obligate mutualism with fig wasps, (Agaonidae); figs are only pollinated by fig wasps, and fig wasps can only reproduce in fig flowers. Generally, each fig species depends on a single species of wasp for pollination. The wasps are similarly dependent on their fig species in order to reproduce. F. obliqua is pollinated by two species of fig wasp—Pleistodontes greenwoodi and P. xanthocephalus.[18] The assumption that fig species are usually pollinated by just one species of fig wasp has been challenged by the discovery of cryptic species complexes among what was previously thought to be single species of fig wasps.[19]
The animals that eat the figs disperse the seeds, which then germinate and grow on other plants (epiphytes) or on rocks (lithophytes). As the new plants develop, they send roots to the forest floor. Figs growing on other plants grow larger and larger until they strangle their hosts. Ficus obliqua is long-lived, and trees are thought to live up to 500 or even 1000 years.[10]
Ficus obliqua is an elegant shade tree for parks or fields, and is adaptable to differing soils. Its timber is too soft for use in woodworking.[9] Although it is much less used in bonsai than F. rubiginosa,[20] it is well-suited for use in the medium; its small leaves and trunk's propensity to thicken,[21] its attributes optimal for a tree 10–80 cm (4–32 in) in height. It is seen in bonsai nurseries mainly in the Brisbane area, where it is a locally common species, and is very highly regarded by at least one proponent, Bradley Barlow.[22] Barlow's specimen from Brisbane won a prize at the Bonsai Clubs International competition in 2006.[23] It is also suited for use as an indoor plant in low, medium or brightly-lit indoor spaces.[24] The fruit is edible and palatable.[25]