Rhododendron hirsutum

Hairy Alpenrose (Rhododendron hirsutum )

The Hairy Alpenrose (Rhododendron hirsutum ) is a plant of the genus Rhododendron and belongs to the family of the heather family ( Ericaceae ). The well-known alpine plant is also known as Almrausch, pastures noise or rock rose.

Origin of the name

The scientific genus name is derived from the Greek " rhodon " = rose and " dendron " = tree from. The epithet derives from the Latin " hirsutum " = shaggy and refers to the hairy leaves.

Description

The evergreen shrub with strong bushy growth habit reaches heights of 20 to 100 cm. The thick stems and branches are densely branched. Young shoots are scattered hairy and little scaly.

The short- stalked and alternate arranged leaves are between one and three inches long, and up to 1.5 inches wide. Their shape is usually narrow - elliptic to narrow - verkehrteiförmig. The leaf margin is finely crenate to entire. The leaf margin is distinctly ciliated, with the horizontally protruding cilia are about one to three millimeters long and are quite stiff. The leaves are dotted on both sides green and glandular. The glands are at first yellowish, later brownish. The top is shiny bright green and bare.

The hermaphroditic about 1.5 Zentimer long -stalked flowers are at the ends of branches in capitate crowded grapes. The crown is bell-shaped vase-shaped and bright bright red. It is up to 1.5 inches long and as wide. She is outside with glandular scales and hairy inside. The stamens are of unequal length and hairy at the base.

The flowering period is from May to July (e rare to October).

The from August ripening fruit capsules are oval and woody. They jump from the tip on with five doors and enter a number of very small, light -brown seed -free.

Occurrence

The Hairy Alpenrose is Austroalpine spread with an emphasis in the Northern and Southern Limestone Alps. In the mountain ranges of the Central Alps, they can only be found in places (Airborne).

As location calcareous mountain pine bushes and dwarf shrubs are preferred in the first place. Furthermore, it is also found on limestone debris, boulders and rocky slopes as well as in sparse pine and mountain pine forests. The Hairy Alpenrose thrives at altitudes 600-2500 m. In deep layers it occurs mainly in humid gorges, especially at dealpinen locations.

Outside the natural range this species is planted, but it is hardly naturalized.

Confusion

In contrast to Rostblättrigen Alpenrose this species grows only on limestone and is distinguished by the leaf eyelashes as well as the green leaf. The two types are vicariously.

The hybrids Rhododendron × intermedium ( Rh hirsutum × Rh ferrugineum ) is morphologically and ecologically between the parents. It occurs mainly in neighboring crops of the parents to frequently and usually forms permanent holdings. Is found mainly in the hybrid flooring with intermediate pH.

Ecology

The ciliated Alpenrose is an evergreen shrub with leather leaves. She is a Kennart of Erico - Rhododendretum ( Schneeheide Alps Rose bushes ).

Although an alpine plant, it needs a closed snow cover in winter, as it is sensitive to frost. The stomata of the leaves are already moving in strong winds from 1 m / s and close even with a good water supply at wind speeds of 1.5 m / s throughout. Done The annual course of frost resistance, as in the conifers on the adjustment of osmotic values ​​. Under a water vapor-saturated snow cover, the plant can survive. At ausgeaperten points freezes the Hairy Alpenrose. There is an ericaceous mycorrhiza.

The flowers are vormännliche " bell flowers with spreading device ". The pollen is mealy and is in tetrads, which are connected by threads sticky. The scars are very slimy. Below the ovary abundant nectar is released, which is covered by the stamen hairs. As pollinators act langrüsselige Hummeln.Wegen the long-haired flower stems and chalices satisfies the lightest touch to shake out the pollen. Also a self-pollination is possible. The flowering season is from May to July.

The fruits are 5- fächrige, septicidal capsules, which open when dry. They are wind - and animal shakers. The seeds are numerous, very small, flat, winged and have a loose seed coat. They will spread as granules flyer; they are light to germinate. Fruit ripening begins in August.

Toxicity

Like many other Rhododendron species are also the Alpine roses because of their Andromedotoxin ( Acetylandromedol ), which is among the diterpenes, highly poisonous. Particularly at risk are ruminants that eat these plants due to lack of winter forage selection.

The Alpenrose is also poisonous to humans, with all plant parts ( flowers, leaves, fruits and roots ) contain the poison Acetylandromedol. Symptoms include salivation, nausea, vomiting, abdominal pain and diarrhea. At higher dose also serious heart rhythm disorders, respiratory disorders, and seizures may occur, which may cause respiratory arrest to the death by heart and.

First aid measures are ample fluid intake and the medical administration of medical charcoal. Other treatments by the doctor follow.

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