Eupomatia

Eupomatia is a genus of three flowering shrub species known to science, of the Australian continent ancient family Eupomatiaceae. The Eupomatiaceae have been recognised by most taxonomists and classified in the plant order Magnoliales. The three species of shrubs or small trees grow naturally in the rainforests and humid eucalypt forests of eastern Australia and New Guinea. The type species Eupomatia laurina was described in 1814 by Robert Brown.

Description

Ecology

Protogynous and autocompatible flowers, with a reduction in selfing through herkogamy, diurnal synchronization of anthesis and the tendency of the same plant to not flower on two consecutive days. Anthesis lasts one or two days, at the height the flower behaves functionally as a female, showing its gynoecium and with open staminodes, while the stamens remain below the flower. The flower later behaves as a male with the intrastaminal staminodes folded inwards hiding the gynoecium and with erect stamens. The staminodes secrete an oily exudate and emit a fruity smell that attracts beetles, particularly of the genus Elleschodes (Curculionidae), that visit the flowers in both phases, in addition the synandria fall to the ground (cantharophily pollination).[5] The fruit is sweet and aromatic and it is dispersed by birds and mammals (zoochory). The fruit is also eaten by humans.

The species are native to the tropical habitats of the rain forest,[6] from sea level to an altitude of 1,300 m.

Phytochemistry

Plants contain unusual lignans and alkaloids (sampangine, eupolauridine, eupomatidine-1, liriodenine and lanuginosine, antimicrobials and antifungals) such as proanthocyanidins, cyanidin and flavonoids, in particular velutin. Iridoids, flavonols and ellagic acid are absent. Cyanogenesis absent.

Uses

The colourful wood of E. laurina is valued as is its fruit, which is used to make traditional Australian drinks, preserves and pastries.

Systematic position

Eupomatiaceae associates specifically with the family Annonaceae in the order Magnoliales from their botanical descriptions. The Angiosperm Phylogeny Website considers Eupomatiaceae a sister group of the family Annonaceae in the terminal clade in the order’s evolution (see AP-website). The APG II system, of 2003 (unchanged from the APG system, of 1998), also recognizes this family, and assigns it to the order Magnoliales in the clade magnoliids.

Species

Commonly named northern small bolwarra. Endemic only in north-eastern Queensland, Australia. Shrubs up to 1 m tall.
Commonly named small bolwarra. Endemic only in north-eastern New South Wales and south-eastern Queensland, Australia. Shrubs up to 1.4 m tall, little branching; leaves oblanceolate to oblong, 80-200 mm by 25-50 mm, petiole decurrent on the stem; flowers up to about 25 mm diameter, pedicels 5 mm; stamens 8-12 mm, yellow with the inside stained red; dark red staminodes; fruits obconic, 20-30 mm diameter, green turning yellow on ripening.
Commonly named bolwarra or copper laurel. Grows naturally in New Guinea and eastern Australia. Shrubs or small trees up to 10 m tall, highly branched; leaves shiny, oblong-elliptical, 70-120 mm long by 20-50 mm wide, petiole non-decurrent of 3 mm; flowers 20 mm in diameter; stamens white to cream, off-white staminodes; fruits greenish-yellow of 15-20 mm diameter, brown when ripe. Pollinated only by the weevil Elleschodes hamiltonii.

Notes

There was no agreement in the references consulted as to whether the calyptra derived from the calyx or a bract. It is interesting to note that perianths do not appear when the calyptra develops,[8] so that, as mentioned, the plants have flowers without petals. When the calyptra’s first floral organs appear stamens and staminodes emerge arranged in a regular pattern following the Fibonacci sequence joined in sequences of 13 and 21 (E. bennettii) or only 13 (E. laurina). The carpels are also arranged in the same way in spirals of eight and 13 (E. bennettii) and of five and eight (E. laurina).[9]

References

  1. ↑ William Jackson Hooker (1785-1865) - Curtis's botanical magazine vol. 81 ser. 3 nr. 11 tab. 4848 (http://www.botanicus.org/page/467824)
  2. ↑ Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x.
  3. ↑ Carlquist, Sherwin (1992). "Vegetative Anatomy and Relationships of Eupomatiaceae". Bulletin of the Torrey Botanical Club. Torrey Botanical Society. 119 (2): 167–180. doi:10.2307/2997029. JSTOR 2997029.
  4. ↑ Botanic Gardens Trust: PlantNET - NEW SOUTH WALES FLORA ONLINE
  5. ↑ Armstrong, Joseph E.; Irvine, Anthony K. (Dec 1990). "Functions of Staminodia in the Beetle-Pollinated Flowers of Eupomatia laurina". Biotropica. 22 (4): 429–431. doi:10.2307/2388563. JSTOR 2388563.
  6. ↑ University of Connecticut. College of Liberal Arts and Sciences - Ecology and Evolutionary Biology Plant Growth Facilities.
  7. ↑ The Global Biodiveristy Information Facility: Eupomatia barbata
  8. ↑ Encyclopædia Britannica
  9. ↑ Endress, Peter K. (2003). "Early Floral Development and Nature of the Calyptra in Eupomatiaceae (Magnoliales)". International Journal of Plant Sciences. 164: 489–503. doi:10.1086/375319. JSTOR 10.1086/375319 – via JSTOR. (registration required (help)).
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