Diospyros (PROSEA Dyes and tannins)

Plant Resources of South-East Asia Introduction

List of species

Diospyros L.

Protologue: Sp. Pl. 2: 1057 (1753); Gen. Pl. (ed. 5): 478 (1754).

Family: Ebenaceae

Chromosome number: x= 15; 2n= 30: D. malabarica var. malabarica

Major species and synonyms

Diospyros malabarica (Desr.) Kostel. var. malabarica , Allg. med.-pharm. Fl. 3: 1099 (1834), synonyms:

• Diospyros embryopteris Pers. (1807),
• Diospyros peregrina Guerke (1891).

Diospyros malabarica (Desr.) Kostel. var. siamensis (Hochr.) Phengklai, Thai. For. Bull. 11: 46 (1978), synonyms:

• Diospyros siamensis Hochr. (1904),
• Diospyros embryopteris Pers. var. siamensis (Hochr.) Lecomte (1930).

Diospyros mollis Griffith, J. Agr. Hort. Soc. Ind. 3: 145 (1844).

Vernacular names

D. malabarica var. malabarica :

• Malabar ebony (En)
• Indonesia: culiket (Sundanese), kledung (Javanese)
• Malaysia: komoi, kumun
• Burma: plab, tako suam
• Cambodia: dângkaô khmaôch
• Laos: küa namz, hnang hèèwx, lang dam
• Thailand: tako thai (general), tako suan (northern), phlap (peninsular)
• Vietnam: thidâù heo, cu'ò'm thi.

D. malabarica var. siamensis :

• Siamese persimmon (En)
• Burma: maplup
• Cambodia: tang kor
• Laos: m'kup tawng
• Thailand: maphlap (general), makap tong (northern), makhuea thuean (north-eastern).

D. mollis :

• Cambodia: mak' klüë
• Laos: küa
• Thailand: ma kluea (general), mak-kluea (Trat)
• Vietnam: mac nu'a.

Origin and geographic distribution

D. malabarica var. malabarica has a fairly large area of distribution, extending from eastern India and Sri Lanka, Burma, Cambodia, Laos and Vietnam, to Thailand (mostly cultivated) and Indonesia (Java, Sulawesi). The geographic distribution of var. siamensis and D. mollis is limited to Burma, Cambodia, Laos and Thailand.

Uses

Unripe fruits are used to dye cloth black, and for tanning nets and sometimes hides. Occasionally, the leaves are used for dyeing. In India, the gum from the fruits of Malabar ebony is used to preserve the bottoms of boats, to caulk seams, and as a glue in book binding.

The fully ripe fruit of both varieties of D. malabarica is edible, but usually not very palatable. It tastes of raspberry and persimmon.

The tannin in the young fruits has many medicinal uses. The juice is applied to wounds and ulcers and is drunk in cases of dysentery and fevers; it possesses anti-bacterial and anthelmintic activity. In Thailand the bark of D. mollis is used to preserve alcoholic beverages.

The timber is used for cabinet work, furniture, and handicrafts. D. malabarica is sometimes cultivated as an ornamental.

Properties

The fruits of D. malabarica var. malabarica contain about 15% tannin, the bark 12%. The tannins are probably derived from leucoanthocyanidins. The colouring matters in the fruits are derivates of naphthoquinones; in fruits of D. mollis 0.7-0.9% diospyrol (C₂₂H₁₈O₄) is found. Fruits of D. mollis also contain betulinic acid, oleanoic acid, methyl esters of palmitic acid, margarinic acid, stearic acid and oleic acid, lupeol, amyrine, and ß-sitosterol. Probably Diospyros fruits also contain saponins, which might contribute to the anthelmintic action and which might explain their use as fish poison. In Thailand, the anthelmintic medicine prepared from D. mollis is reported to have a toxic effect on human eyes. The fruits of D. malabarica var. malabarica contain about 50% pectin.

The wood of Malabar ebony is moderately heavy (ca. 780 kg/m³) and moderately hard, greyish and close-grained. The heartwood of the tree is often rotten; when it is sound, it is variegated black and brown. The wood of D. mollis is very heavy, ca. 1300 kg/m³(the heaviest wood in Thailand), hard and durable.

Description

• Trees or shrubs, all parts often turning blackish when dry.
• Leaves alternate and distichous, simple and entire.
• Inflorescences axillary or cauliflorous.
• Flowers usually unisexual, 3-7-merous, with superior ovary.
• Fruit a leathery or fleshy berry, few-seeded.

D. malabarica var. malabarica is a dioecious or polygamous, small to medium-sized tree, up to 15 m (rarely up to 35 m) tall, with trunk up to 70 cm in diameter; trunk often fluted, crown conical with spreading branches; bark dark grey, more or less rough and scaly. Leaves leathery, elliptic-oblong, 7-32 cm × 2-10 cm, obtuse to acute, glabrous, yellowish when dry, shortly petiolate. Male flowers in 3-9-flowered cymes in the leaf axils, with numerous stamens, female flowers in 1-5-flowered cymes, with a globose, 4-styled ovary; corolla with short lobes. Fruit globose, 5-7.5 cm in diameter, turning yellow or orange when ripe; persistent calyx with patent-reflexed lobes. Seeds 4-8, albuminous, with ruminate endosperm.

D. malabarica var. siamensis differs in the persistent calyx which is broadly campanulate or flat with ascending lobes.

D. mollis is characterized by ovate and smaller leaves, 4-8 cm × 1.5-4 cm, blackish when dry, smaller flowers with deeply lobed corolla, smaller fruits, black when ripe, and seeds with smooth endosperm.

Growth and development

The woody seeds germinate in 30-60 days. Seedlings grow very slowly in the first 3-4 years. The mean annual girth increment of the Malabar ebony tree is reported to be 1.5-2.3 cm in India.

D. mollis does not flower until about the age of 30 years, but Siamese persimmon flowers earlier, at about 15 years of age. The flowers are insect-pollinated. Because male and female flowers do not bloom simultaneously breeding is hampered.

D. malabarica var. malabarica flowers in Java in September and October. D. malabarica var. siamensis flowers in Thailand from February to May, it fruits from May to December. D. mollis flowers from January to September and fruits from August to December.

Other botanical information

Diospyros is a very large genus. Only a few species are primarily dye and tannin-producing plants; most are important as timber. Therefore the description of the genus is kept concise here. Other Diospyros species, which are known to be used in dyeing and tanning include D. rhodocalyx Kurz, D. gracilis Fletcher, D. martabanica C.B. Clarke, D. dictyoneura Hiern and D. apiculata Hiern from Thailand, D. pyrrhocarpa Miq. from Thailand and India, and D. samoensis A. Grey from Polynesia and New Guinea.

Ecology

The varieties of D. malabarica are often found in shady and wet sites near streams in the forest, up to 500 m altitude. They occur naturally in places with up to 3000 mm annual precipation. In cultivation, Malabar ebony thrives on many types of soil, provided it is not too dry. D. mollis grows in dry, mixed, deciduous forest, up to 500 m altitude, in places with an annual rainfall of up to 2000 mm.

Propagation and planting

Plants are propagated by seed, because propagation experiments by stem cuttings have never been successful. After collecting, the seeds should be cleaned from the pulp, dried in the shade and sown within 2 weeks. Experiments have shown that viability decreases rapidly during storage. Usually seeds are sown in a nursery at the beginning of the rainy season, after being soaked for 24 hours. Spacing is 10 cm within rows and 25 cm between rows, and the seed-beds are covered with a 9:1 mixture of coarse sand and black ash. The beds must be shaded and watered when conditions are dry. Seedlings are often transplanted into containers with soil containing 20% coarse sand, 10% black ash and 5% green manure. They are carefully transplanted to the field when ca. 15 cm tall, without damaging the long taproot. In a plantation of trees, a spacing of at least 8 m × 8 m is necessary because of the wide spreading crown. Trees are cultivated as a sole crop.

Husbandry

Weeding is necessary at least 2-3 times a year during early stages of development. Generally, fertilizer is applied 1-2 times per year.

Diseases and pests

The insects Myllocerus setulifer and Stromatium barbatum are reported to feed on the leaves of Malabar ebony. Some fungi may damage trees: Diplodia embryopteridis is found on the fruits, Ceuthospora diospyri and Phyllosticta diospyri on the leaves, Hexagonia polygramma in the wood.

Handling after harvest

Unripe, still green fruits are used to dye cloth and tan nets. The average annual yield is 200 kg per tree for Siamese persimmon and 300 kg for D. mollis. The fruits cannot be kept longer than 5 days without losing much of their dyeing and tanning capacity, unless kept in water to which some lime has been added. Clothes are immersed in a solution of finely crushed fruits in water to which sometimes a mordant is added, and are then dried in the sun. When this handling is repeated about 20 times, the clothes take on a black, fairly fast colour. Sometimes the textiles are first dyed dark blue with indigo.

Prospects

The Diospyros species treated here have several interesting uses and might be promising trees for South-East Asia. Research on silviculture and uses is desirable, especially for D. mollis. Malabar ebony is recommended as a road-side tree, as it is relatively resistant to air pollution.

Literature

• Crevost, Ch. & Pételot, A., 1941. Catalogue des produits de l'Indochine. Tome 6. Tannins et tinctoriaux. Gouvernement général de l'Indochine, Hanoi. pp. 61-63.
• Phengklai, C., 1981. Ebenaceae. In: Smitinand, T. & Larsen, K. (Editors): Flora of Thailand. Vol. 2. TISTR Press, Bangkok, Thailand. pp. 310, 329-331.
• Sastri, B.N. (Editor), 1952. The wealth of India. Raw materials. Vol. 3. Council of Scientific and Industrial Research, New Delhi. pp. 85-86.
• Sturm, G. & Zilliken, F., 1972. On the chemical constituents of Diospyros mollis fruits. Planta Medica 21(1): 61-66.

Authors

W. Subansenee & C. Phengklai