Cyclamen
2008/9 Schools Wikipedia Selection. Related subjects: Plants; Recreation
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 Cyclamen persicum growing wild,
Ben Shemen forest, Israel |
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Cyclamen africanum |
Cyclamen is a genus of 20 species of flowering plants, traditionally classified in the family Primulaceae, but in recent years reclassified in the family Myrsinaceae. The genus is most widely known by its scientific name cyclamen being taken into common usage; other names occasionally used include sowbread and sometimes, confusingly, persian violet (it is not related to the violets), or primrose (neither is it a primrose).
Cyclamen are native to the Mediterranean region from Spain east to Iran, and also in northeast Africa south to Somalia. They are perennial herbaceous aestivating plants, with a surface or underground tuber (derived from the hypocotyl) 4-12 cm diameter, which produces leaves in late winter, and flowers in the autumn; the leaves die down during the hottest part of the Mediterranean summer drought to conserve water. Each leaf or flower grows on its own stem, which shoots up from the hypocotyl. The variegation is thought by some botanists to be a form of natural disruptive camouflage to reduce grazing damage by animals.
The hypocotyl grows leaves and flowers on stems, either one flower or one leaf per stem. The stem for leaves and flowers appears identical except in height. The leaves grow on stems of around 6cm height.
The leaves grow on stems up to 8cm tall and form a tightly bunched circular disk of leaves. Leaves are rounded to triangular, 2-10 cm long and 2-7 cm broad, and usually variegated with a pale silvery horseshoe-shaped mark round the middle of the leaf.The top of the leaf is split with the split extending to the connection with the stem. A commom cultivar available in western shops has a leaves with a (slightly stretched) heart shape.
The stems for flowers rise from the middle of the disk of leaves. The stem for flowers grows up to 12 cm tall, and the end of the flowers stem curves 150 - 180 degrees downward. The flower bud terminates the stem. The various cultivars produce flowers with either four or five united petals growing from the edge of the flower bud. The petals are usually reflexed back 90° to 180° to be erect above the flower bud, and vary from white through pink to red-purple, most commonly pale pink.
The fruit is a five-chambered capsule 1-2 cm diameter, containing numerous sticky seeds about 2 mm diameter. Natural seed dispersal is by ants, which eat the sticky covering and then discard the seeds. Cyclamens are used as food plants by the larvae of some Lepidoptera species including The Gothic.
Cyclamen typically grow in dry forest or scrub, where they are at least partly shaded from intense sunlight. The species vary greatly in winter frost tolerance, with the hardiest species (C. hederifolium) tolerating temperatures down to -15°C, or -30°C if covered by snow; others, such as C. somalense from northeastern Somalia, do not tolerate any frost at all. Certain climate change models suggest many species could become extinct in their current range within the next 50 years (Yesson & Culham 2006 ).
Cultivation and uses
Cyclamen are commonly grown for their flowers, both outdoors and indoors in pots. Several species are hardy and can be grown outdoors in mild climates such as northwest Europe and the Pacific Northwest.
The cyclamen commonly sold by florists is C. persicum, which is frost-tender. Selected cyclamen cultivars can have white, bright pink, red or purple flowers. While flowering, florists' cyclamens should be kept below 68 °F (20 °C, 293 kelvins), with the night time temperatures preferably between 44 °F to 59 °F (6.67 °C to 15 °C, or 280 K to 288 K). Temperatures above 68 °F (20 °C, 293 K) may induce the plant to go dormant.
In many areas within the native range, cyclamen populations have been severely depleted by collection from the wild, often illegally, for the horticultural trade; some species are now endangered as a result. However, in a few areas, plant conservation charities have educated local people to control the harvest carefully at a sustainable level, including sowing seed for future crops, both sustaining the wild populations and producing a reliable long-term income. Many cyclamen are also propagated in nurseries without harm to the wild plants.
Cyclamen species are poisonous; they have been used medicinally as a powerful purgative, but their toxicity makes this risky.