RHODODENDRON
Ferruginous rhododendron
Family : Ericaceae
Category : perennial
Height : 70 to 150 cm
Color : pink
Flowering : June to August
Habitat : between 1700 and 2000 m
Protection : yes
Toxicity : yes
Frequency : frequent in the central Alps, rare in the Pre-Alps
DESCRIPTION
Persistent sub-shrub from 70 to 150 cm high with very branched upright branches. Tough oval leaves arranged in dense tufts at the tips of the twigs. Reverse side of pronounced rust colour. Stalk of leaves short, and whole edge slightly curved downwards. Many bright red flowers in umbelliform inflorescences at the tips of the branches. Calyx welded in funnel and corolla opening wide with 5 rounded lobes.
HISTORY
The name rhododendron comes from the Greek rhodo (pink) and dendron (tree). The term ferruginous is associated with the rust colour of the underside of the leaves. In medieval times, rhododendron was called "rosage", a term that was kept until the 18th century, when Joseph Piton de Tournefort introduced the "rosage of Black Sea" in 1702, following a trip to Asia Minor. The name rhododendron is due to the naturalist Linné. Rhododendron was first actually cultivated as a horticultural species by John Tradescant in 1656, who brought back a rhododendron hirsutum from the Alps. However, the real success of rhododendron began with Himalayan and Chinese species (rhododendron auriculatum and seroticum) in the middle of the 19th century.
HABITAT
Common in the central Alps, but rarer in the Pre-Alps; rock scree, clear-woods, dwarf sub-shrub moors; on acidic clay soils, rich in humus and silicate; at an altitude of about 1700 to 2000 m.
PARTICULARITIES
The plant is very sensitive to frost and grows in areas of prolonged snowfall, which provides it with protection against frost. It can be parasitized by two fungi Exobasidium rhododendrii which causes benign tumours and Chrysomyxa rhododendrii which causes bright orange spots. In homeopathy, the leaves of the ferruginous rhododendron are used against rheumatism, gout and neuralgia.
THREAT
This flower is protected, do not pick it ! In addition, it is very toxic (even animals do not eat it).
Shaggy rhododendron
Family : ericaceae
Category : perennial
Height : 70 to 150 cm
Color : pink
Flowering : June to August
Habitat : between 1500 and 2500 m
Protection : yes
Toxicity : yes
Frequency : frequent except in the central Alps
DESCRIPTION
Persistent sub-shrub 70 to 150 cm high with curved, highly branched branches with tough oval leaves up to 3 cm long; they are grouped at the tips of the branches and have long silky hairs on their edges. Leaf margin finely toothed, not rolled up downwards. Flowers in umbelliform inflorescences at the tips of the branches. The 5 funnel-shaped fused light red petals emerge from the chalice and open with 5 tips.
HISTORY
The foliar edges covered with hirsute eyelashes gave the shaggy rhododendron its name. In medieval times, rhododendron was called "rosage", a term that was kept until the 18th century, when Joseph Piton de Tournefort introduced the "Black Sea Rosage" in 1702, following a trip to Asia Minor. It is to the naturalist Linné that we owe the name of rhododendron. Rhododendron was first actually cultivated as a horticultural species by John Tradescant in 1656, who brought back a rhododendron hirsutum from the Alps. However, the real success of rhododendron began with Himalayan and Chinese species (rhododendron auriculatum and seroticum) in the middle of the 19th century.
HABITAT
In the middle and eastern limestone Alps, rarely in the central Alps; clear-woods, association of sub-shrubs at the upper limit of the trees; on limestone and stony soils; between 1500 and 2500 m altitude.
PARTICULARITIES
Persistent hair leaves are a characteristic of shaggy rhododendron, which only grows on limestone soil.
THREAT
This flower is protected, do not pick it ! Moreover, it is very toxic.
Dwarf rhododendron
Family : ericaceae
Category : perennial
Height : 10 to 40 cm
Color : pink
Flowering : May to July
Habitat : between 1500 and 2200 m
Protection : yes
Toxicity : yes
Frequency : frequent except in the Western Alps
DESCRIPTION
Sub-shrub from 10 to 40 cm high with very branched and curved branches, and alternating oval leaves, tough, up to 1.5 cm long. At the tips of the twigs, 1 to 3 flowers appear with long ciliated petioles. 5 thin sepals fused together only at the base. From the corolla of 2 to 3 cm in diameter, composed of 5 rounded light pink petals, emerge 10 long stamens.
HISTORY
In medieval times, rhododendron was called "rosage", a term that was kept until the 18th century, when Joseph Piton de Tournefort introduced the "rosage of Black Sea" in 1702, following a trip to Asia Minor. The name rhododendron is due to the naturalist Linné. Rhododendron was first actually cultivated as a horticultural species by John Tradescant in 1656, who brought back a rhododendron hirsutum from the Alps. However, the real success of rhododendron began with Himalayan and Chinese species (rhododendron auriculatum and seroticum) in the middle of the 19th century.
HABITAT
Spread in the eastern limestone Alps and on basic rocks in the central Alps, absent in the western Alps; cracks and screes of rocks, bushes of mountain pines; on limestone, stony and wet soils; between 1500 and 2200 m altitude.
PARTICULARITIES
The leaves of the dwarf rhododendron have a full edge like those of the shaggy rhododendron but are half as long.
THREAT
This flower is protected, do not pick it ! Moreover, it is very toxic.