Puarangi (Hibiscus trionum)
Description
Hibiscus trionum, commonly called flower-of-an-hour, bladder hibiscus, bladder ketmia, bladder weed, flower-of-the-hour, modesty, puarangi, shoofly, and venice mallow, is an annual plant native to the Old World tropics and subtropics. It has spread throughout southern Europe both as a weed and cultivated as a garden plant. It has been introduced to the United States as an ornamental where it has become naturalized as a weed of cropland and vacant land, particularly on disturbed ground. The plant grows to a height of 20–50 centimetres (7.9–19.7 in), sometimes exceeding 80 centimetres (31 in), and has white or yellow flowers with a purple centre. In the deeply pigmented centre of the flower, the surface features striations, which have been the subject of controversy about whether they act as a diffraction grating, creating iridescence. Initial studies showed that artificial replicas of the flower surface produced iridescence that bees could recognise. Later work suggested that the irregularities of the plant cells and surface resulted in the periodicity of the striations being too irregular to create clear iridescence and thus suggested that the iridescence is not visible to man and flower visiting insects. More recent papers have presented evidence that the flower is both visibly and measurably iridescent,and the striations have been shown to be sufficiently irregular to generate particularly strong scattering of light at short wavelengths, producing weak iridescence and a 'blue halo' (of which the halo is the dominant visible effect). It has also been demonstrated that the blue scattering increases the foraging efficiency of bumblebees in laboratory environments, although it remains unknown whether this effect translates to a meaningful advantage in the field.
Taxonomic tree
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Domain: Eukarya
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Kingdom: Plantae
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Phylum: Magnoliophyta
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Class: Magnoliopsida
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Order: Malvales
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Family: Malvaceae
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Genus: Hibiscus
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