Rhododendron arboreal [3] ( lat. Rhododéndron arborescens ) is a deciduous shrub , a species of the Pentanthera section , the subgenus Pentanthera [4] , the genus Rhododendron ( Rhododendron ), and the Heather family ( Ericaceae ).
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Rhododendron arborescens ( Pursh ) Torr. , 1824 [2] |
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- Azalea arborescens pursh basionym
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Used as an ornamental garden plant.
Botanical illustration of Rhododendron arborescens ; John Curtis, 1819
Rhododendron tree-shaped, buds
Deciduous upright shrub 2-3 m high. Young shoots are bare, often covered with a thin coating. Annual growth of 5-10 cm.
The leaves are thin, from obovate to oblong-lanceolate, 4-8 cm long, 1.5-3.0 cm wide, sharp or blunt with a wedge-shaped base, ciliate on the edge, shiny above, bright green, bluish green below, in autumn crimson or bright yellow with orange spots, glabrous on both sides, but veins can sometimes be covered with very rare hairs. Petioles 5-7 mm long.
Flowers 3–6, bloom after full development of the leaves, funnel-shaped, up to 6 cm wide, white with a pinkish tinge, very fragrant , glandularly stiff-hairy on the outside, with a 2.5-3.0 cm long cylindrical tube slightly expanded upward. Stamens 5, they are much longer than the corolla , their threads from the base to the middle are pubescent, in the upper part are purple. The ovary is glandular-bristly with reddish glands. Column approximately the same length with stamens, usually bare, purple-red at the top.
Fruits - boxes, ripen in November [3] [5] .
It has been known in culture since 1818 [3] .
It withstands temperature drops to −26 ° С [4] . Flowering in July for a month.
In GBS since 1965. At 15 years old, height 50–80 cm, crown diameter 75 cm. It grows rapidly. It blooms in July, an average of about 19 days. Does not bear fruit. Winter hardiness is good. Seed germination of 40-70%. When processing cuttings with root stimulants, about 86% are rooted. Decorative during flowering and autumn [5] . In the Nizhny Novgorod region winter-hardy . In severe winters, the ends of shoots and flower buds freeze. Seeds ripen [6] .
Successfully grown in Finland in Mustila Arboretum [7] .
