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Leaves and Flowers. Copyright CSIRO
Scale bar 10mm. Copyright CSIRO
10th leaf stage. Copyright CSIRO
Scientific NameMirabilis jalapa L.
Linnaeus, C. von (1753) Species Plantarum 2: 177. Type: Habitat in India utraque.
Common Four-O'clock; Marvel-of-Peru; Four-o'clock
Flowers and fruits as a shrub about 1-2 m tall.
Leaf blades about 3-9 x 2-3.5 cm, rather thin and papery. Short tortuous hairs present on the upper surface along the midrib and major lateral veins. Lateral veins forming loops inside the blade margin. Petiole channelled on the upper surface. Twigs slightly swollen above each pair of leaves. Twig surfaces mainly smooth except for two bands of short tortuous hairs on opposite sides of the twigs.
The structure of the flowers is rather confusing. What appears to be a green calyx is actually green floral bracts. What appears to be the corolla is actually a corolliform calyx. Perianth to about 6.5 cm long, limb about 2.5-3.5 cm diam. All stamens are of different lengths, anthers +/- reniform. The ovary is surrounded and enclosed by five fleshy aristate scales which are probably the reduced petals. Stigma comparatively large and tuberculate.
Fruits globular, about 7-8 mm long, longitudinally ribbed. Testa thin and papery. Endosperm granular or powdery. Embryo on the margin of the seed, the cotyledon margin recurved and surrounding the endosperm.
Cotyledons about 20-25 x 30-45 mm, wider than long. At the tenth leaf stage: leaf blade triangular or cordate, apex acuminate. Petiole grooved on the upper surface. Taproot thick and dark, carrot-shaped (Daucus carota). Seed germination time 68 days.
Distribution and Ecology
An introduced species originally from Peru, now naturalised in NEQ and south-eastern Queenslands and southwards as far as south eastern New South Wales. Altitudinal range in NEQ from near sea level to 750 m. Usually found as a garden escapee but grows in disturbed rain forest on the Atherton Tableland.
Natural History & Notes
This species is slightly poisonous. If ingested it causes stomach pain and vomiting. If the roots are handled they can cause dermatitis. (http://www.ces.ncsu.edu/depts/hort/consumer/poiso n/Mirabja.htm (17-8-2000)).
Roots leaves and seeds poisonous. Austin, D. F. 1998. Poisonous Plants of Southern Florida. (http://www.fau.edu/divdept/science/envsci/poison- pl.html)
This species may have medicinal properties and it is also poisonous. (http://squid2.laughingsquid.net/hosts/herbweb.com /herbage/A17339.htm)
Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)
CC-BY Australian Tropical Herbarium unless otherwise indicated in the images.