• Journal of Forest and Environmental Science
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• v.40 no.2
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• pp.123-140
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• 2024

More than half of the global distribution of the Rhododendron genus is found in China, with over 74% being endemic species. However, there is still insufficient data to chemically classify the Rhododendron genus native to China. Therefore, in this study, a chemotaxonomic study was conducted to determine the presence of taxifolin-3-O-arabinopyranoside, a flavonoid compound, in the Rhododendron genus native to China. Forty-three species of Rhododendron native to China-20 from across China, 8 from Beijing, 6 from Yanbian, and 9 from Yunnan-were utilized in the experiment. Through HPLC analysis, the retention time was compared with that of taxifolin-3-O-arabinopyranoside, a standard compound, and quantitative analysis was conducted. As a result, taxifolin-3-O-arabinopyranoside was detected in 22 out of 43 the Chinese Rhododendron species. Afterwards, LC-MS/MS analysis was performed on the 22 species in which taxifolin-3-O-arabinopyranoside was detected to determine whether the molecular weight was consistent with the standard compound. Under negative conditions, it was confirmed that all samples exhibited the same molecular weight as taxifolin-3-O-arabinopyranoside, 435-436 m/z. The same compound was detected in more than half of the Rhododendron species used in the experiment, and taxifolin-3-O-arabinopyranoside was determined to be an indicator compound for Rhododendron species native to China. In addition, the possibility of using the above results as basic data for chemical classification of Chinese Rhododendron genus was confirmed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.3
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• pp.129-136
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• 2001

The alpine grassland vegetation at the northwest slope of Mt. Paektu were investigated by Penound- Howard's cover-degree method. The floristic composition of the alpine grassland from 2,100m altitude to the top of mountain were 35 species, 1 subspecies, and 6 varieties, and most of the plants were short p e r e ~ i a l herbs and shrubs. The dominant species of the vegetation distributed along to altitude were Rhododendron aureum (2,100-2,20Om), Dryas octopetala var. asiatica(2,200-2,30Om), Dryas octopetala var. asiatica(2,300-2,40Om), Rhododendron aureum- Rhododendron redowskianum(2,400-2,50Om), and Rhododendron redowskianum(2,500- 2,58Om), respectively. Characteristics of the shrub plants which settled in alpine grassland showed uniform low height(3-15cm), creeping stem and evergreen leaf. Life form of the plants were 29 species of Hemicryptophyte, 8 species of Chamaephyte, 1 species of Geophyte, and 5 species of Phanerophyte. (Key words : Alpine grassland, Mt. Paektu, Altitude, Dominant, Life form)

• Journal of Forest and Environmental Science
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• v.38 no.3
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• pp.159-173
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• 2022

Genus of Rhododendron has been used in traditional medicine since ancient times and is known to be effective in immune function, inflammation, and cold symptoms. And the reason for this activity is the flavanonol type among flavonoids in the genus of Rhododendron. Among the flavanonol types, Taxifolin-3-O-arabinopyranoside was isolated from the root of native R. mucronulatum in Korea, and the structure was finally identified through HPLC, LC-MS/MS, ¹H-NMR, and ¹³C-NMR. Taxifolin-3-O-arabinopyranoside is a compound mainly found in R. mucronulatum, a representative species of the genus of Rhododendron, and exhibits antioxidant, anti-inflammatory, and anti-atopic activities. In this study, Taxifolin-3-O-arabinopyranoside was chemotaxonomic significant in 5 species of the genus Rhododendron native to Korea (R. mucronulatum, R. mucronulatum var. ciliatum, R. schlippenbachii, R. yedoense var. Poukhanense, R. japonicum for. Flavum). Compared with the existing literature, Taxifolin-3-O-arabinopyranoside was identified for the first time in 4 species of Rhododendron except for the R. mucronulatum.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1319-1328
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• 2011

Rhododendron brachycarpum is a evergreen broad-leaved shrub and belongs to the Ericaceae family and the Rhododendron genus. It is well known for its beautiful leaves and flowers. There are 11 species of the Rhododendron genus in Korea. It includes 3 species - Rhododendron brachycarpum, Rhododendron aureum Georgi and Rhododendron brachycarpum var. roseum Koidz. They grow naturally over 1,000 meters above sea level of the Baekdu Mountain Range in Korea. These habitats, according to investigations of 9 Rhododendron brachycarpum natural habitats, are mostly located on the slope of mountains facing north at an altitude of 1,200 m to 1,526 m above sea level with angle of inclination from 30 degrees to 45 degrees. Based on the result of vegetation analysis of dominance species in the quadrates, there are Quercus aliena, Quercus mongolica Fisch. ex Ledeb, Abies holophylla in species of upper trees, and so on. Dominant species of woody plants in tree layer are Quercus aliena, Quercus mongolica Fisch. ex Ledeb, Abies holophylla, Betula platyphylla and Veeatrum patulum Loes. fil, Erythronium japonicum, Dryopteris crassirhizoma, Paeonia japonica var. glabra Makino are founded in herbaceous plants. And we can see another result of the investigation that the flowering rates of the plants with the buds are highly ranked mountains such as Mt. Hambaek 68%, Mt. Gyebang 40%, Mt. Yagksu 9%, Mt. Gaein 7% and Mt. Seolag 0%. The results show that there are 24 over 15-year-old Rhododendron brachycarpums in Mt. Odae and are 56 under 15-year-old trees in Mt. Hambaek and are no trees in Mt. Gyebang and are 9 over 30-year-dead trees only in Mt. Taebaeg. Out of found trees, the highest tree is 7 m in height and 0.6 m in diameter. Also this result shows what are the vulnerability factors of the natural habitats. They are as follows: indiscriminate trails in mountains, damages by mountain climbers, uncareful plant collecting, the fierce competitions with other plants such as Acer pseudosieboldianum var. ishidoyanum Uyeki, Quercus aliena, Celastrus orbiculatus and damages by disease and insect, unusual temperature in natural habitats, etc. Rhododendron brachycarpums have high ornamental value and excellent pharmaceutical effect. But the areas of its habitats decrease dramatically. So we need measures to protect and their natural habitats. It is necessary that we conductfurther investigations to designate conservation area for Rhododendron brachycarpums.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.24-47
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• 1998

This study examined ecophysiological characteristics, cultivation methods and planting uses of tree and shrub species native to Kangwon province and valuable as landscape plants. The results were as followos : 1. 73 species selected as shrubs were ; Rhododendron brachycarpum, Rhododendron micranthum, Abelia mosanensis, Abeliophyllum distichum, Acanthopanax sessiliflorus, Acanthopanax senticosus, Alangium platanifolium var. macrophyllum etc. 2. 38 species selected as trees were ; Cornus controversa, Sorbus commixta, Malus baccata, Prunus padus, Acer triflorum, Acer tegmentosum, Styrax japonica, Styrax obassia, Sorbus alnifolia etc. 3. Shade-tolerant species were ; Abies koreana, Rhododendron brachycarpum, Rhododendron micranthum, Prunus padus, Sorbus commixta, Acer triflorum, Rhus japonica, Cornus kousa, Kalopanax pictus, Chionanthus retusa, Sorbus alnifolia, Magnolia sieboldii, Sorbaria sorbifolia var. stellipila, Berberis koreana, Lindera obtusiloba, Rhododendron schlippenbachii and Euonymus alatus. 4. Species growing well even in less fertile soils were ; Pinus thunbergii, Quercus dentata, Koelreuteria paniculata, Rhus japonica, Quercus acutissima, Albizzia julibrissin, Sorbus alnifolia, Staphylea bumalda, Philadelphus schrenckii, Clerodendron trichotomum, Deutzia coreana, Weigela florida, Zanthoxylum schinifolium and Lindera obtusiloba. 5. Salt-tolerant species were ; Pinus thunbergii, Quercus aliena, Prunus padus, Styrax japonica, Quercus dentata, Kalopanax pictus, Chionanthus retusa, Albizzia julibrissin, Tilia amurensis, Forsythia koreana, Lonicera maackii, Symplocos chinensis for. pilosa, Clerodendron trichotomum, Sambucus williamsii var. coreana, Abelia mosanensis, Deutzia coreana, Viburnum carlesii, Rhus japonica, Rhododendron yedoense var. poukhanense, Zanthoxylum schinifolium, Callicarpa dichotoma, Rhododendron schlippenbachii and Euonymus alatus. 6. Pollutant-tolerant species were ; Styrax japonica, Prunus padus, Quercus dentata, Kalopanax pictus, Chionanthus retusa, Gleditsia japonica var. koraiensis, Styrax obassia, Forsythia koreana, Kpiraea salicifolia, Clerodendron trichotomum, Viburnum sargentii, Viburnum carlesii, Weigela florida and Rhododendron yedoense var. poukhanense.

• Journal of Forest and Environmental Science
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• v.34 no.6
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• pp.435-450
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• 2018

Phenological events of four Rhododendron tree species (viz. R. arboreum, R. arboreum ssp. delavayi var. delavayi, R. barbatum and R. kesangiae) was monitored in temperate mixed broad-leaved forests of Arunachal Pradesh, India. Phenological events like flower bud formation, flowering, fruit setting, fruit maturing, seed dispersal, leaf bud formation, leaf flushing, and leaf shedding were recorded. Indices i.e., phenophase sequence index (PSI), active phenophasic period of the species (APS) and index of reproductive/vegetative activity (RVA) were also calculated. Present study revealed that bark consistency, growth form and leaf pattern of the studied species have showed variations among the species. Rhododendron species exhibited the phenological events overlapping with other phenophases. The peak flower bud formation was observed during the winter; R. arboreum ssp. delavayi var. delavayi start flowering from December, while the flowering in rest three species exhibited during February to April. Fruit setting occurred during summer to autumn while fruit maturation revealed peak during November. Leaf bud formation illustrated two peaks in April and May, leaf flushing exhibited peak in June, while leaf shedding peaked during October to November. Active phenophasic period of the species were found 12 months, which revealed that species engage in various phenophase activities throughout the year. Phenophase sequence index ranged between 0.8 to 0.9 (PSI ${\geq}0.6$), signifies that species have a sequential arrangement of phenophases. Index of reproductive/vegetative activity of the species exemplified >1, indicate that the reproductive phenophases were dominance over vegetative phenophases. The study have provided substantial insight on the life cycle events of Rhododendron species and ecological approaches for further scientific study with recent climate change and effective management and conservation.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.229-233
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• 2017

We isolated endophytic fungal strains from roots of Rhododendron schlippenbachii growing in Minjujisan mountain, Korea. The two strains were identified as Engyodontium album and Phaeosphaeria microscopica based on their morphological characteristics and sequence analysis of the internal transcribed spacer (ITS) and large subunit regions of the ribosomal DNA. These two species, E. album and P. microscopica, have not been previously reported in Korea.

• The Korean Journal of Ecology
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• v.21 no.5_2
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• pp.519-529
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• 1998

The vegetation of alpine and subalpine zone from timber line, 2,000m altitude, to the upper area of Mt. Packtu were investigated by phytosociological method. The plant distribution along to the different altitudes shown as follows: Betula ermani community with Rhododendron redowskianum occupied dominantly at 2,000m area as patch forms, Rhododendron redowskianum community with Vaccinium uliginosum, at 2,180-2,200m area, both Vaccinium uliginosum and Rhododendron redowskianum community were compatible with each other at 2,243m area. Rhododendron redowskianum community at 2,250, Salix rotundifolia community, Erigeron thunbergii var. glabrata community, Dryas octopetala var. asiatica community and Carex atrata community were occurred frequently at 2,263m around Chonji Lake. Rhododendron aureum, Thunbergii coccinea and V accinium uliginosum showed higher cover degree than other species at 2,370m area, Phyllodoce coerulea-Rhododendron aureum community at 2,400m, Rhododendron redowskianum community at 2,470m, Rhododendron aureum community at 2,490m, Salix rotundifolia at 2,520m, Rhododendron redowskianum community at 2,580m, Dryas octopetala var. asiatica community, Salix rotundifolia, and bistorta achotensis etc. at 2,650 altitude area were settled as sparse, creeping shape on the surface soil and dwarf plants of about 15cm heights.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.223-225
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• 2008

Rhododendron species is one of the largest and most diverse genera in the plant kingdom, comprising over 800 species and existing all over the globe. Grayanotoxin intoxication is caused by ingestion of honey and flowers. Grayanotoxin exists in honey, flowers, pollen, and nectar of the Rhododendron species. Grayanotoxin-intoxicated patients may present with nausea, vomiting, dizziness, weakness, hypotension, bradycardia, and syncope for several hours. We report a case of grayanotoxin intoxication associated with mental changes. A 9-year-old male presented with impaired consciousness and delirium 26 hours after eating about 10 rhododendron sclippenbachii flowers. A brain MRI and EEG were normal. Parenteral fluids were administered and these symptoms resolved completely in 17 hours.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.113-126
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• 2011

This study was carried out to improve planting and use of landscape plants in Gangwon-do. The designated plants by schools and cities in Gangwon-do were surveyed and then compared with the planted trees on streets, public parks, schools, etc. in 2009. There were 45 tree species and 43 flower species designated as school trees and school flowers at 632 schools in Gangwon-do. The majority of school tree species were Juniperus chinensis, Pinus densiflora, Abies holophylla, Ginkgo biloba, Pinus koraiensis, Taxus cuspidata, Zelkova serrata, and Pinus thunbergii. The ratio of native species to exotic was 35:10. The majority of school flower species Rosa centifolia, Forsythia koreana, Zinnia elegans, Rhododendron mucronulatum, Chrysanthemum morifolium, and Rosa rugosa. The ratio of native species to the exotic was 22:21. There were 12 flower species and 7 tree species designated as city trees and city flowers in 18 cities and guns. The high frequency flower species were Rhododendron schlippenbachii, Forsythia koreana, Magnolia sieboldii, and Prunus armeniaca var. ansu. The high frequency tree species were Ginkgo biloba, Pinus koraiensis, and Taxus cuspidata. There were 87 woody landscape tree species planted, and a total of 619,835 landscape plants were planted in Youngseo region (western part of Gangwon-do) in 2009. The ratio of native species to exotic species was 56:31. The majority of landscape trees planted were Pinus densiflora, Prunus yedoensis, Prunus sargentii, Comus officinalis, Pyrus pyrifolia, Rhododendron yedoense var. poukhanense, Pinus koraiensis, Taxus cuspidata, Hibiscus syriacus, Forsythia koreana, Zellkova serrata, Acer triflorum, Rhododendron obutusum, and Ligustrum obtusifolium A in 2009. The ratio of native species to the exotic was 64:36. There were 77 woody landscape tree species planted, and a total of 914,668 landscape plants were planted in Youngdong region (eastern part of Gangwon-do) in 2009. The ratio of native species to exotic was 52:25. The major landscape trees planted were Pinus thunbergii, Rhododendron lateritium, Rhododendron schlippenenbachii, Hibiscus syriacus, Prunus yedoensis, Pinus densiflora, Syringa dilatata, Rhododendron yedoense var. poukhanense, Rosa rugosa, Prunus sargentii, Rosa centifolia, Juniperus chinensis, Euonymus japonica, Forsythia koreana, Chionanthus retusus, Acer palmatum, and Chaenomeles sinensis. The results indicate that landscape plants need to be diverse in species in each region of Gangwon-do. Selection of suitable plants for each region and the use of native species need to be emphasized.