Rhododendron acutifolia   ( lat. Rhododendron mucronulatum ) - a perennial deciduous shrub plant from the genus rhododendrons .
Rhododendron spiky, grade 'Wheeldon Pink'
|International scientific name|
Rhododendron thymifolium Turcz. , 1837
Chinese name: 迎 红 杜鹃 (Ying hong do juan)  .
It is found in Russia in the extreme southwest of the Primorsky Territory , in Mongolia , Korea , China ( Jiangsu , Liaoning , Inner Mongolia , Hubei and Shandong ) and Japan ( Honshu and Kyushu ).
It grows in the undergrowth and at the edges of birch, dark coniferous and cedar-broad-leaved forests on the slopes of the mountains   .
Deciduous branched shrub , 1-3 m high. Young shoots are rusty-brown, adult shoots are gray.
The leaves are thin, elliptical or elliptically lanceolate, pointed or sharp, 3-8 × 1-3.5 cm, bright green, petiole 3-5 mm long. By the end of summer, the leaves turn brown and do not twist into a tube in autumn, most of them fall.
Inflorescences are subapical, bear 1-6 flowers.
Blooms before the leaves bloom. Pedicel 0.5-1 cm, rarely scaly; calyx 5-lobed, 0.5-1 mm, scaly, glabrous or rarely bristly; corolla is funnel - shaped, pale reddish-violet, or lilac-pink, 2.2-3.5 cm long, 3-5 cm in diameter, the outer surface is pubescent. Stamens in an amount of 10, not of equal length, slightly shorter than toward the corolla tube; filaments pubescent from below. Rhododendron var. albiiloruin nakai white flowers.
The fruit is an oblong capsule , 1-1.7 cm long. Seeds ripen in late September    .
2 varieties are described:
- Rhododendron mucronulatum var. ciliatum
- Rhododendron mucronulatum var. mucronulatum
In the horticultural literature, Rhododendron mucronulatum var. taquetii . Slow-growing, dwarf form (10 years old, height about 30 cm), found during a botanical expedition to Jejudo Island in southern Korea in May 1976. Plants grown from seeds are grown as ornamental garden plants. This form probably blooms later on typical plants. The flowers are pink to purple, wide-funnel-shaped. Inflorescences are single-flowered. There is no aroma. Leaves from elliptical to lanceolate. They endure temperature drops to -29 ° C   .
Some taxonomists consider the spiky rhododendron a subspecies of the rhododendron daursky - Rhododendron dauricum L. subsp. mucronulatum ( Turcz. ) Vorosch.
In culture since 1882 (in Europe), and in the Far East region much earlier.
In GBS since 1953. At 15 years old, the shrub has a height of 1.65 m, the bush diameter is 80-100 cm (250 cm), the diameter of the largest trunks is 2-2.5 cm. The annual growth is 10-15 cm. The shoots located in the lower part of the crown finish growth early , in the upper - continue to grow until August inclusive.
It blooms in May or the end of April annually, especially intensively on branches that overwintered under the snow. The duration of flowering is two to three weeks.
Flower buds located at the top of the crown often die in winter; at the same time, the ends of the annual shoots that did not have time to lignify before the onset of cold weather freeze. Shelter of plants for the winter or bending them to the ground eliminates freezing of branches and provides annual abundant flowering. Leaves appear after flowering, usually in the second half of June. Leaf fall begins in mid-September; some leaves sometimes remain until spring.
Seeds in Moscow rarely ripen in October. Shoots are lignified by 75-100%. Winter hardiness I — II  . In Khabarovsk bears fruit  . In the conditions of the Nizhny Novgorod region, it is relatively winter-hardy (in this respect it is close to the Daurian rhododendron ). Seeds are ripening  .
- Rhododendron mucronulatum var. mucronulatum 'Cornell Pink'
- Rhododendron spiky - the official natural symbol of the city of Vladivostok
- A traditional Korean delicacy, Chintallae Hwajon (진달래 화전), rice cake " ttok " with rhododendron petals is prepared with rhododendron.
Diseases and Pests
The buds of Rh. mucronulatum 'Wheeldon Pink'
Finland , Helsinki
Joseon , XIX century
- For the conventionality of specifying the class of dicotyledons as a superior taxon for the plant group described in this article, see the APG Systems section of the Dicotyledonous article .
- Alexandrova M.S. Rhododendrons of the natural flora of the USSR. - M .: Science, 1975.
- Kondratovich R. Types and varieties of rhododendrons suitable for cultivation in the Latvian SSR // Rhododendrons . - Riga: Zinatne, 1981.
- Rhododendron mucronulatum . efloras.org. Date of treatment March 4, 2015.
- Poletiko O. M. Rod. 3. Rhododendron - Rhododendron // Trees and shrubs of the USSR. Wild, cultivated and promising for introduction. / Ed. volumes S. Ya. Sokolov . - M. - L .: Publishing House of the Academy of Sciences of the USSR , 1960. - T. V. Angiosperms. Families Myrtle - Olive. - 544 p. - 2200 copies.
- Hans Eiberg. Rhododendron mucronulatum var. taquetii . rhododendron.dk. Date of treatment March 8, 2016.
- Rhododendron mucronulatum var. taquetii . American Rhododendron Society. Date of treatment March 8, 2016.
- Mishukova I.V., Khrynova T.R. Results of the introduction of rhododendrons at the Research Institute of Botanical Gardens of the Nizhny Novgorod State University // Bulletin of the Nizhny Novgorod University. N.I. Lobachevsky. - 2014. - No. 3-3 .