Synonyms: R. lancifolium. R. speciosum.
Common Name : Rhododendron
Habitat: Rhododendron ponticum is native to southern Europe and southwest Asia. It grows in the rich forests under Fagus, Picea and Abies species, it is also found above the tree line. Sandy and peaty soils in woods and open places in Britain.
Rhododendron ponticum is a dense, suckering shrub or small tree growing to 5 m (16 ft) tall, rarely 8 m (26 ft).Leaves are oblong or elliptic-lanceolate, 10-20 cm long and 2.5-64 cm wide, dark green above, paler below; petiole 1.3-2.5 cm long and they are evergreen. The flowers are 3.5 to 5 cm (1.4 to 2.0 in) in diameter, violet-purple, often with small greenish-yellow spots or streaks. The fruit is a dry capsule 1.5 to 2.5 cm (0.59 to 0.98 in) long, containing numerous small seeds.
It is in leaf 12-Jan It is in flower from May to June. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects.
The two subspecies are:
Rhododendron ponticum is an invasive plant. It produces abundant seed and also suckers, forming dense thickets. It is naturalized in Ireland, the U.K. and much of western Europe as well as in parts of New Zealand. Rhododendron control is a key element in nature conservation in many areas.
Succeeds in a most humus-rich lime-free soils except those of a dry arid nature or those that are heavy or clayey. Prefers a peaty or well-drained sandy loam. A pH between 4.5 and 5.5 is ideal. Succeeds in sun or shade, the warmer the climate the more shade a plant requires. Hardy to about -15°c. Plants are self-sowing aggressively in British woodlands and are often out-competing native trees by filling the understorey and preventing natural regeneration. They are considered to be a pernicious weed by many environmentalists. Succeeds in a woodland though, because of its surface-rooting habit, it does not compete well with surface-rooting trees. Plants need to be kept well weeded, they dislike other plants growing over or into their root system, in particular they grow badly with ground cover plants, herbaceous plants and heathers. Plants form a root ball and are very tolerant of being transplanted, even when quite large, so long as the root ball is kept intact. Plants in this genus are notably susceptible to honey fungus.
Seed – best sown in a greenhouse as soon as it is ripe in the autumn and given artificial light. Alternatively sow the seed in a lightly shaded part of the warm greenhouse in late winter or in a cold greenhouse in April. Surface-sow the seed and do not allow the compost to become dry. Pot up the seedlings when they are large enough to handle and grow on in a greenhouse for at least the first winter. Layering in late July. Takes 15 – 24 months. Cuttings of half-ripe wood, August in a frame. Difficult.
A medicine made from the plant is used to treat heart and circulation malfunctions, but it should not be used without expert supervision.
Rhododendron ponticum subsp. baeticum is one of the most extensively cultivated rhododendrons in western Europe. It is used as an ornamental plant in its own right, and more frequently as a rootstock onto which other more attractive rhododendrons are grafted. The plants were first grown in Britain in the 1760s, supplied by Conrad Loddiges, and became widely distributed through the commercial nursery trade in the late 18th and early 19th centuries. The roots readily send up suckers from below the graft, often allowing it to overtake the intended grafted rhododendron.
Known Hazards: Honey produced with pollen from the flowers of this plant can be quite poisonous, causing severe hypotension and bradycardia in humans if consumed in sufficient quantities, due to toxic diterpenes (grayanotoxins).
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.
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