Dendranthema (PROSEA)

Plant Resources of South-East Asia
Introduction

Dendranthema (DC.) Des Moul.

Protologue: Actes Soc. Linn. Bord. 20: 561 (1860).

Family: Compositae

Chromosome number: x= 9; D. ×grandiflorum, D. indicum: 2n= 18, 36, 42, 45, 52, 54, 60, 70, 72, 90 (polyploids and aneuploids are of cultivated plants)

Vernacular names

(Garden) chrysanthemum, mum (En).

Major species

Dendranthema × grandiflorum (Ramat.) Kitam.,
D. indicum (L.) Des Moul.

Origin and geographic distribution

About 37 species of Dendranthema are recognized, of which 2 occur in Europe and the others in Central and South-East Asia. In South-East Asia, both species present are cultivated for ornamental purposes and have sometimes become naturalized. In India, Vietnam, Taiwan, China and Japan Dendranthema is cultivated as a medicinal plant.

Uses

Worldwide, Dendranthema species are best known as ornamentals. In Indo-China, a decoction of the flower heads of D. × grandiflorum and D. indicum is used as a depurative, against fevers, headaches, and eye infections. The Chinese also inhale the powder for treatment of colds and headaches. The use of Dendranthema flower heads and leaves in pillows is thought to benefit the blood circulation, and to preserve vitality. The white-flowered form of both species is considered to be especially useful in preventing the hair from falling out or turning grey. The flower heads are also soaked in wine, producing a "chrysanthemum wine", and used for a great variety of digestive, circulatory, and nervous difficulties. In China and Vietnam, the leaves and flower heads are used to treat hypertension. In the Philippines, the leaves of D. indicum are applied against flatulence. In China, an infusion of the flower heads is used similarly. The flower heads are considered by the Hindus to be heating and aperient and useful in affections of the brain and in calculus, as well as an antidote to a mental depression.

Concerning the wild form of D. × grandiflorum in Indonesia, the whole plant is thought to be slightly poisonous. It is employed in decoction in the treatment of retained menses, as a wash for infected sores, and as a fomentation for enlarged glands. The flower heads are used in China against fever and headache, and together with black pepper to cure gonorrhoea.

Dendranthema flower heads are eaten as a vegetable, especially in Japan where they are considered a delicacy. In China and Japan, the flower heads of D. × grandiflorum, especially the yellow ones, are used for local production of insecticides.

Production and international trade

Dendranthema is cultivated all over the world on a commercial basis as an ornamental. As a medicinal plant it is grown commercially in India, Vietnam, China, Taiwan and Japan. In South-East Asia it is grown in gardens for ornamental and medicinal purposes. No statistics are available on production and trade of Dendranthema as a medicinal plant.

Properties

D. × grandiflorum contains an essential oil, of which the main components are camphor (16-58%), eucalyptol (9-30%), 2,6,6-trimethyl-2,4-cycloheptadien-1-one (18%), borneol (13%) and isoborneol (10%). Further phytochemical investigations revealed the presence of 3 sesquiterpenes (chrysanthediol, chrysanthediacetates B and C) as well as β-dictyopterol in the neutral alcoholic extract of the flower heads. 3,4-Dihydroxyacetophenone and 3,4-dihydroxyphenylacetone were isolated from fresh leaves of 10-week-old cuttings.

The water extract of D. × grandiflorum contains the phenolic compound ellagic acid, which was found to be a potent aldose-reductase inhibitor. The enzyme aldose-reductase could be responsible for an increased intracellular accumulation of sorbitol in diabetic animals. Inhibiting this enzyme might prevent diabetic complications, including cataracts, neuropathy, retinopathy and nephropathy. Furthermore, ellagic acid also shows marked antioxidant activity, together with effective hydrogen-donating abilities, indicating that it is an effective radical scavenger.

The water extract of D. × grandiflorum flower heads contains the flavonoid acacetin-7-O-β-D-galactopyrasonide and the flavone chrysin, which exhibit anti-HIV activity.

D. × grandiflorum ligulate flowers containing 2-hydroxy-taraxastane-type triterpenes, fardiol and heliantriol C, markedly inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA) induced inflammation, as measured by the ear oedema model in mice. These compounds also significantly inhibited the promoting effect of TPA on skin tumour formation, following topical 7,12-dimethylbenz-[a]-anthracene application in vivo.

Many Compositae are known to cause contact dermatitis; a study among market gardeners and florists in Germany often indicated D. indicum as the cause. Contact dermatitis caused by D. × grandiflorum has been investigated in India. The most common type was hand and face dermatitis, followed by airborne contact dermatitis. All patients demonstrated positive patch tests to ethanol extracts of the flower heads, the leaves, the whole plant or the stems. These contact allergies are attributed to the presence of guaianolide type sesquiterpene lactones, e.g. arteglasin-A and alantolactone.

The leaves and flower heads of D. indicum yield an essential oil, called kiku oil (0.2% on dry weight base), its principal components being thujone (20%), camphor (13%), eucalyptol (8%), borneol (7%), α-pinene (5%), sabinene (5%) and camphene (4%). Further compounds include the glucoside chrysanthemin, the sesquiterpene chrysanthetriol, the guianolide tunefulin and the ketodiols chrysetunone and indicumenone from the aerial parts.

Intravenous administration of D. indicum extract decreased aortic and renal blood pressure in anaesthetized open-chest dogs, and increased aortic, vertebral and coronary blood flow. The extract produced directly and uniformly coronary and systemic vasodilation with renal vasoconstriction. D. indicum extract has a protective effect on myocardial injury of neonatal rat heart cells deprived of oxygen and glucose. Furthermore, a clinical study of D. indicum preparations in the treatment of bovine mastitis by intramammary infusion showed that the extract was very effective in relieving inflammatory symptoms, but less effective than penicillin and streptomycin in treating intramammary infection.

D. indicum is an effective growth and development inhibitor of the bug Dysdercus similis. In vitro studies of the leaf extract tested for nematicidal activity showed that egg hatching of Meloidogyne incognita nematodes was greatly inhibited.

Adulterations and substitutes

Essential oils of other Compositae, e.g. Blumea species, contain similar compounds and might substitute Dendranthema extracts.

Description

Aromatic perennial herbs, up to 1.5 m tall, sometimes woody at base, erect, often much branched.
Leaves alternate, pinnatifid to pinnatilobed; petiolate; stipules absent.
Inflorescence consisting of terminal or axillary heads, heads solitary or in lax corymbs, rather large and radiate, very variable in size; receptacle flat, strongly convex; involucre semi-globose, cup-shaped, consisting of 3-many-seriate, imbricate, broadly scarious-margined bracts.
Marginal flowers ligulate, female, disk flowers tubular, bisexual, 4-5-dentate, flowers mostly yellow (many other colours possible when cultivated); style-arms truncate, with a penicillate top.
Fruit a cylindrical to obconical achene, 5-8-ribbed, glabrous, pappus absent or consisting of a membranous rim or short scales.
Seedling with epigeal germination.

Growth and development

After the first year Dendranthema becomes woody at the base, its growth is somewhat stunted and flower heads are smaller; therefore it is grown commercially as an annual. Depending on the cultivar, one to many flower heads per stem are formed.

Other botanical information

Despite the obvious horticultural interest for Dendranthema cultivars, there are only regional reviews of the naturally occurring species. Autumn-flowering Dendranthema are probably a complex hybrid group raised in China from D. indicum and D. × grandiflorum, and around 5000 cultivars are recognized in the United Kingdom, but many more exist around the world. In China first yellow, then white, then purple cultivars were developed: 500 cultivars existed in 1630. They were introduced into Europe in 1688, but were established in France only in 1789. Cultivars with a single row of ligulate flowers usually produce much pollen, cultivars with only ligulate flowers are normally sterile. Korean chrysanthemums are hybrids between D. × grandiflorum and D. zawadskii (Herbich) Tzvelev cultivars. In Japan, cultivars which flower in (late) summer are considered inferior in petal taste to those flowering in autumn.

Dendranthema belongs to the tribe Anthemideae, and forms together with Argyranthemum, Chrysanthemum, Leucanthemum and Tanacetum the Chrysanthemum complex. It is possible that Dendranthema will be reduced again to a group below the genus level and that its species will resume the Chrysanthemum names. Three main classes of compounds of chemosystematic interest are present in the Anthemideae: polyacetylenes, flavonoids and sesquiterpene lactones.

Ecology

Dendranthema cultivars are planted in a wide variety of regions, from sea-level to 1000 m altitude. They prefer sunny, fertile locations with loose, moist soil. The optimum temperature range is from 15°C to 30°C.

Propagation and planting

Many Dendranthema cultivars do not produce seed and are propagated by cuttings. They are taken from stock plants, old plants which are cut back and form new shoots. The cuttings are planted in fertile, moist soil to promote rooting. Tissue culture and plant regeneration studies from protoplasts have been done with Dendranthema, but only for ornamental purposes.

Husbandry

In China planting time of D. indicum cuttings is from March till June, and harvest is 5 months later. Many pot- or field essays have been performed on cultivars to identify optimum nutrient demand, day length sensitivity, optimum temperature, optimum planting time and chilling tolerance. Short days of 8 hours decrease plant height and increase flower head diameter, whereas long days of 14 hours have the opposite effect. On average, Dendranthema species flower after 85 days under 8 hours photoperiod, and after 130 days under 14 hours photoperiod.

Diseases and pests

A wide range of diseases and pests are recorded for Dendranthema cultivars. Diseases are caused by Phytophthora spp., Sclerotinia nivalis, Septoria chrysanthemella, Alternaria spp. and Fusarium oxysporum f. chrysanthemi. The most common pests are aphids, thrips, nematodes and white fly.

Harvesting

Leaves and flower heads of Dendranthema are collected from cultivated or wild plants whenever needed.

Genetic resources and breeding

In the United States a small germplasm collection of Dendranthema species is present. In Dendranthema self-incompatibility and cross-fertilization are the rule in diploids, but polyploids show weak self-incompatibility. D. indicum and D. × grandiflorum have been crossed with other Dendranthema species in China to provide cultivars suitable for ground cover. These cultivars have a dwarf or creeping habit, and small flower heads of 4-5 cm in diameter. They are resistant to low temperatures, drought, alkaline or saline soils, semi-shade, and pollution.

Prospects

Dendranthema species contain a multitude of compounds which display interesting pharmacological activities, e.g. ellagic acid, acacetin-7-O-β-D-galactopyrasonide and taraxastane-type triterpenes. The medicinal value of these compounds should be evaluated by specific research.

Literature

Desai, M.N. & Patil, A.V., 1981. Photoperiodic influences on Chrysanthemum indicum L. and Chrysanthemum morifolium L. Journal of Maharashtra Agricultural University 6(2): 100-102.
Heywood, V.H. & Humphries, C.J., 1977. Anthemideae - systematic review. In: Heywood, V.H., Harborne, J.B. & Turner, B.L. (Editors): The biology and chemistry of the Compositae. Vol 2. Academic Press, New York & San Francisco, United States and London, United Kingdom. pp. 851-898.
Hu, C.Q., Chen, K., Shi, Q., Kilkuskie, R.E., Cheng, Y.C. & Lee, K.H., 1994. Anti-AIDS agents, 10. Acacetin-7-O-β-D-galactopyranoside, an anti-HIV principle from Chrysanthemum morifolium and a structure-activity correlation with some related flavonoids. Journal of Natural Products 57(1): 42-51.
Kitamura, S., 1978. Dendranthema and Nipponanthemum. Acta Phytotaxonomica and Geobotanica 29(6): 165-170.
Li, H.-L., Liu, T.-S., Huang, T.-C., Koyama, T. & DeVol, C.E. (Editors), 1978. Flora of Taiwan. Vol. 4. Compositae. Epoch Publishing Co., Taipei, Taiwan, Republic of China. pp. 768-965.
White, E.A., 1930. The chrysanthemum and its culture. New York, United States. 192 pp.

Selection of species

Authors

G.H. Schmelzer