AgroForestryTree Database
Rhodomyrtus tomentosa
 Species identityEcology and distributionPropagation and managementFunctional usesPests and diseasesAdditional InfoBibliographyImages |
Species identity
TaxonomySynonym(s)
Common names
(Cambodia) : sragan
(Filipino) : rose myrtle
(Indonesian) : harendong sabrang (Sundanese)
(Malay) : karamunting (Sabah, Sarawak)
(Thai) : phruat (Trat)
(Vietnamese) : sim
Botanic description
Evergreen shrub or small tree, up to 4 m tall; twigs, young leaves and inflorescences densely white or yellowish tomentose. Leaves elliptic to oblong-elliptic, 4.5-8 cm x 2.3-4 cm, opposite, coriaceous, with 3 conspicuous longitudinal veins, upper surface glossy, glabrous, lower surface white or yellowish tomentose with raised nerves; petiole 3-5 mm long. Flowers solitary or in 3-flowered dichasia in upper axils; peduncles up to 1 cm, pedicels 0.5-2.5 cm long; bracts elliptic, leaf-like, 6-12 mm long, bracteoles elliptic or ovate, 2-3 mm long, persistent; calyx campanulate, 5-7 mm long, tomentose, 5-10-ribbed, 5-lobed, persistent; petals 5, broadly obovate, 15-18 mm x 9-13 mm, red or pink; stamens numerous, 10-15 mm long, filaments pink; style 13-15 mm long; ovary 3(-4)-locular. Fruit an oblongoid berry, 10-15 mm x 8-10 mm, purplish-black, crowned by the calyx lobes, tomentose; wall 1 mm thick, pulp sweet. Seeds many in 6(-8) pseudo-locules, divided by thin false septa, compressed-reniform, 1.5 mm in diameter. Two varieties are distinguished: - var. tomentosa (synonym Myrtus canescens Lour.), occurring in South-East Asia, southern China and Indo-China; with white-tomentose leaves, lateral nerves 2-6 mm inside the margin, less than one-third of the distance from the leaf margin to the central nerve, apex not apiculate, veins not reticulate, pedicels 1-2.5 cm long; - var. parviflora (Alston) A.J. Scott (synonym Rhodomyrtus parviflora Alston), occurring in India and Sri Lanka; with cream- or yellowish-tomentose leaves, lateral nerves 3-7 mm inside the margin, over one-third of the distance from the leaf margin to the central nerve, apex apiculate, veins reticulate, pedicels less than 1 cm long.
Ecology and distribution
History of cultivationDowny myrtle is growing wild and cultivated South-East Asia, India, Sri Lanka, and southern China. Occasionally it is grown outside this area.
Natural Habitat
Downy myrtle thrives in open, often degraded sandy sites, along the shore and on river banks. Where it grows, other plants seem not to be able to compete with it, hence almost pure stands exist. It tolerates full sun and flooding. Var. tomentosa is generally found in such harsh environments, up to elevations of 300 m, rarely up to 1300 m. On the other hand, var. parviflora occurs in montane woodlands and grassland at altitudes of 1800-2700 m.
Downy myrtle is growing wild and cultivated South-East Asia, India, Sri Lanka, and southern China. Occasionally it is grown outside this area.
Biophysical limitsAltitude (var. tomentosa): Up to 300 m (rarely up to 1300 m), Altitude (var. parviflora): 1800-2700 m. Soil type: Moist, somewhat acid soils are preferred; the plant is not well adapted to limestone soils.
Reproductive Biology
In Java, it flowers in July-August and fruits in September-October.
Propagation and management
Propagation methodsIn cultivation the shrub is normally propagated through cuttings.Tree Management
Plants raised through cuttings will bear fruit in about 2 years. The growth rate is moderate and if enhanced by heavy fertilization, flowering and fruiting suffer.
Functional uses
ProductsFood: Children compete with birds for the sweet, edible fruit. In some areas jam or jelly used to be made from the fruit, but it is only incidentally available in quantity. Medicine: Old sources in Malaysia mention the use of the fruits as a cure for dysentry and diarrhoea. A decoction of the roots or leaves is drunk for diarrhoea and stomachache, and as a protective medicine after birth. In Indonesia, the crushed leaves are used to dress wounds. Tannin or dyestuff: The wood-tar can serve as a black dye and has been used to blacken teeth and eyebrows.Services
Ornamental: In Java and in Florida, where the downy myrtle is cultivated in gardens, the ornamental value of the shrub and its flowers is prized.
Pests and diseasesDowny myrtle is easy to grow and no serious pests and diseases have been reported.
Additional Information
DevelopmentFruit of cultivated plants is said to be far superior to that of wild plants. In Java, downy myrtle is known only as a garden plant. The growth rhythm has not been studied. Fresh seed germinates within a week.Properties
Food: The whole fruit is edible. It contains sugars, vitamins and minerals. The purple pulp is juicy and sweet when fully ripe, otherwise slightly astringent.
Prospects
Downy myrtle is a very showy shrub when in bloom and it would seem that the prospects for its use as an ornamental plant are better than for its role as a fruit crop.