Rhododendron arboreum Sm.

Rhododendron (fr)

Species

Angiosperms > Ericales > Ericaceae > Rhododendron

Characteristics

Trees, usually evergreen, (1–)5–20(–30) m tall; trunk well-defined; bark gray-brownish, exfoliating into thin and small irregular flakes; young shoots stout, with distinct leaf traces, densely grayish tomentose, glabrescent. Winter buds ovoid, 10–12 × 5–6 mm, puberulent. Petiole 10–25 mm with dense fawn indumentum intermixed with glands, sometimes glabrescent; leaf blade leathery, oblong-lanceolate or oblong-oblanceolate, 6–15 × 2–4.5 cm; base cuneate or ± rounded; margin revolute; apex acuminate or acute; abaxial surface with indumentum 1-or 2-layered, densely compacted, white to fawn tomentose, sometimes with loosely floccose brown upper layer, hairs dendroid, glabrescent; adaxial surface reticulate to bullate, glabrous; midrib deeply impressed adaxially; lateral veins 15–26-paired. Inflorescence dense, ca. 20-flowered, rachis 10–15 mm, tomentose. Pedicel ca. 0.9 cm, pilose, glandular; calyx lobes 5, 1–2 mm, small, triangular, sparsely glandular and hairy; corolla tubular-campanulate, pink to deeply crimson, rarely white, 3.5–4 cm, with 5 black-blotched basal nectar pouches and dark flecks; lobes 5, 1.2–1.7 cm, apex emarginate; stamens 10, unequal, 1.7–2.7 cm, filaments glabrous; ovary conoid, 4–6 mm, white-tomentose, sometimes also glandular; style ca. 3.3 cm, glabrous. Capsule cylindric, ca. 30 × 6 mm. Fl. May, fr. Aug.
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A small evergreen tree. It can be 1-8-15 m high. It can spread 4.5 m high. The leaves have stalks. The leaves are crowded towards the ends of the branches. Leaves are 4.5-16 cm long by 1.5-6 cm wide. They are oblong to sword shaped and narrow at both ends. They are silvery underneath. The flowers are red, white or pink. The flowers are crowded in large round heads. There are 10 stamens. The fruit capsule is 1.5-2 cm long. It has ribs along it.
Life form perennial
Growth form tree
Growth support free-standing
Foliage retention evergreen
Sexuality hermaphrodite
Pollination entomogamy
Spread -
Mature width (meter) 2.5 - 3.0
Mature height (meter) 9.0 - 12.0
Root system -
Rooting depth (meter) -
Root diameter (meter) 0.5
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Nitrogen fixer -
Photosynthetic pathway c3

Environment

A tropical and subtropical plant. It grows in the highlands of Vietnam between 2,550 and 3,000 m altitude. In Nepal it grows between 1400-3300 m altitude. It grows on hillsides in mixed oak forests. It is native to the Himalayas. It suits hardiness zones 7-9. Arboretum Tasmania.
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Forests and shrubberies with Pieris ovalifolia and Quercus incana; at elevations from 1,500-3,600 metres.
Light 4-7
Soil humidity 3-7
Soil texture 3-6
Soil acidity 2-4
Soil nutriment -
Hardiness (USDA) 8-9

Usage

The flower petals are eaten raw. They are also used to make jelly. The juice from them is used to make drinks. They are also used for colouring drinks and syrups. They are also used for chutney. The flower can be pickled with salt and chili. CAUTION: The young leaves are poisonous. The young leaves are cooked as a vegetable. They are boiled.
Uses charcoal environmental use fuel material medicinal poison wood
Edible flowers leaves
Therapeutic use Parasympatholytics (bark), Anti-inflammatory agents (flower), Cholinergic antagonists (flower), Diarrhea (flower), Dysentery (flower), Antirheumatic agents (leaf), Central nervous system depressants (leaf), Gout (leaf), Headache (leaf), Parasympatholytics (leaf), Anti-poisoning (leaf), Headache (unspecified), Diarrhea (unspecified), Poison (unspecified), Dysentery (unspecified), Fish-Bones (unspecified)
Human toxicity -
Animal toxicity -

Cultivation

Plants are grown from seeds. They are sown in a nursery and picked out in the second season.
Mode cuttings graftings seedlings
Germination duration (days) 50 - 90
Germination temperacture (C°) 12 - 15
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Rhododendron arboreum unspecified picture

Distribution

Rhododendron arboreum world distribution map, present in China and Pakistan

Conservation status

Rhododendron arboreum threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:331945-1
WFO ID wfo-0001229495
COL ID 6X73M
BDTFX ID 56024
INPN ID 117674
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Rhododendron arboreum Rhododendron puniceum Rhododendron windsorii Rhododendron arboreum var. arboreum

Lower taxons

Rhododendron arboreum var. roseum Rhododendron arboreum var. cinnamomeum