black catechu ) for unrefined
khair ) product
|Product type and form traded:||Dried aqueous extract of tree heartwood.|
|Botanical source:||Acacia catechu Willd. (family: Leguminosae); both from wild and cultivated trees.|
|Synonyms for botanical source:||"Cutch" or "catechu" or "khair" tree in India; "sha" in Myanmar; "sa-che" or variants of "seesiat" in Thailand.|
|Distribution:||(a) Natural range is in an arc across southern Himalayas from Pakistan, through Nepal, India, Bangladesh, Myanmar to Thailand and, possibly, extending into Yunnan Province, China; (b) introduced to Indonesia.|
|World production:||Possibly between 6,000-9,000 tonnes per annum.|
|International trade:||Poorly quantified, possibly 1,500 tonnes per annum mainly in Asian region.|
|Major producers:||India (with smaller-scale production in Pakistan, Bangladesh, Myanmar and Thailand).|
|Availability of reliable published information:||Fair.|
"Cutch" is the purified aqueous extract of the heartwood of the multipurpose tree, Acacia catechu Willd. This deciduous, thorny species grows up to 15 m high and is indigenous to the southern range of the Himalayas (extending in India as far south as Andhra Pradesh and Orissa), Myanmar and northern Thailand.
Processing involves three stages: production of a crude extract "black catechu"; isolation of "katha" and solidification of the residue, "cutch".
"Black catechu" has been traditionally employed in the producer countries for crude dyeing, leather tanning and in indigenous medicines.
The further processed "cutch" is employed as a cheap brown dye and preservative for canvas, fishing nets and similar items and also as a tanning agent for leather, particularly in India. In more recent times, cutch has found use as a viscosity modifier in oil well drilling. It is composed mainly of catechu-tannic acid with catechin, catechu red, quercetin and a gum as minor components.
"Katha" is a brown semi-crystalline substance which contains catechin
and its isomers. It is used as an ingredient of "pan" and "pan marsala"
chewing confectionery in India.
Black catechu" is included in several European pharmacopoeias but the current scale of usage, if any, is insignificant. There appear to be no imports of cutch into developed country markets for use as a dyestuff or as a tanning agent.
Trade in cutch appears restricted to the traditional usage areas of the Indian sub-continent and certain countries in Southeast Asia. Imports have been reported for Pakistan, Nepal, Bangladesh and Myanmar, which are not self-sufficient in domestic production, and by China. The scale of this trade cannot be precisely quantified but probably totals only slightly larger than India's exports, i.e., around 1,500 tonnes annually.
Photo 1: Black catechu being sold by street vendor, Myanmar. (Photo: M. Kashio)
The major producer of cutch and katha is India where production is based in the northern provinces on wild and cultivated trees and involves both cottage-scale and industrial-scale processing (with some factories having a throughput capacity of 1,000 tonnes of raw material per month). Up-to-date information is not available for India on output levels or on the breakdown in domestic usage of cutch between dyestuff, tanning and medicinal applications. However, factories have recently reported difficulties in operating at full capacity owing to raw material supply problems; the tree is valued as a fuelwood and for other purposes. During the mid-1970s, some 63,000 tonnes of wood were consumed annually by the katha/cutch industry and this is estimated crudely as providing around 5,000-6,000 tonnes of cutch. India recorded exports of 1,000-1,300 tonnes of cutch annually over 1988-1993 with Pakistan as the major destination.
Minor producers of unrefined "black catechu" include Myanmar, Thailand, Bangladesh and Pakistan. Reliable data are available only for Thailand; current production is cottage-industry type, based on a limited natural resource with sales mainly to the domestic traditional medicine market but involving small exports to Pakistan, Nepal and Bangladesh.
The absence of reliable data makes it impossible to predict a market trend for cutch as a dyestuff or tanning agent. However, a continued substantial demand may be expected in the traditional regional market and this could possibly increase along with population growth, demand for manufactured goods and industrialization. The major perceived constraint lies with the availability of the wood raw material which is already under pressure from alternative uses, particularly as a fuelwood, in many countries.
The following prices were reported in an FAO study for October 1992.
Table 7: Wood and cutch prices for India and Thailand, 1992
|Wood||up to US$ 240/m3||ca. US$ 13/m3|
|Best quality katha||US$ 15/kg||
Source: Kashio, M. (1992).
Quality standards for cutch and katha have been published by the Indian Standards Institution.
Supply shortages for cutch could develop within the main traditional regional markets of Asia owing to the high demand for the raw material as fuelwood. This might offer the opportunity for entrance to the market by new sources, both for export on a modest scale and to supply any domestic demand. Prospective candidates include Nepal and Indonesia; the tree is indigenous in the former and it has been established as an exotic on plantations in the latter. However, the opportunities or constraints for new ventures require a thorough supply and demand study in the region, and this must also take into account trends in usage of alternative, inexpensive natural and synthetic dyestuffs and tannins.
Climate and Soil Requirements
A. catechu is found in moderate rainfall areas over its natural range from the Southern Himalayas down to northern Thailand. It has not proven suitable for the most dry or heavy rainfall areas in India. The altitude limit in the Himalayas is around 1,200 m. It is adaptable to a wide range of well-drained soils, even poor stony types which are unsuitable for many other trees.
In India, the tree is grown on large plantations and in smaller, communal lots (in which it is exploited for fuelwood and village-scale processing purposes).
Several varieties of A. catechu are recognised in India and they possess differing characteristics. The three main types are var. catechu in the Western Himalayas; var. catechuoides in the Eastern Himalayas; and var. chundra in the more southerly areas.
Seeds are employed for propagation and germination is reported as improved by hot-water pre-treatment. Seedlings are raised in nurseries for about six months prior to field planting (at spacings of 2 m x 4 m or greater).
Weeding is the most important action in the early years after establishment.
Rotation regimes depend upon the intended usage: for fuelwood production in India, felling is usually at 10-15 years of age; trunks with a diameter of 30-35 cm are considered the most economic for cutch extraction and this size may not be achieved for 30 years.
Photo 2: Wild growth of Acacia catec, Thailamd. (Photo:M Kashio)
Photo 3: Heartwood of Acacia catechu being
cut and chipped for extraction
of cutch and katha (Photo: M.Kashio)
Photo 4: Crude cutch ("black catechu") attaining consistenci. (Photo: M.Kashio)
Photo 5: Katha, machine cut into for sale. (Photo: M.Kashio)
The dark heartwood of the trunk and of branches greater than 2.5 cm diameter are employed for extraction. Freshly cut material should be employed to optimise extraction yields.
Modern village-scale processing in India involves a number of distinct operations. Heartwood is mechanically chipped prior to the first extraction which is undertaken in metal, open-topped pots of 40 litres capacity. Approximately 10 kg of chips, supported in a wire basket, are boiled with 25 litres of water for 2 hours. The extract is removed and the chips are subjected to a second extraction. The combined extracts are filtered and are then concentrated by boiling in the metal pots until the specific gravity attains approximately 1.05. Katha crystallizes out over a period of several days from the concentrate and this is removed with the aid of a filter press; final preparation of the katha prior to sale involves maceration in clean water, filtering, pressing and drying to around 10% moisture content. The filtrate obtained after removal of the katha is concentrated by evaporation to a viscous state and is then allowed to solidify as cutch.
Factory-scale processing is basically similar but on a larger scale (typically 2.5 tonnes of heartwood per batch extraction) with additional mechanical aids. The extraction may be carried out both at atmospheric pressure or in autoclaves at 100-110?C; the process is repeated on the chips six times with the complete operation taking about 12 hours per batch. The extracts are concentrated in a steam-heated vacuum evaporator and the product is then stored at 0?C for 12 days to crystallize out the katha. The cutch residue is subjected to vacuum concentration and is finally poured into wooden boxes (holding 25 kg) to solidify.
Cutch and katha may be cut into pieces for sale, if required by the buyer, and the katha is sometimes reduced to a powder.
Heartwood yields vary considerably according to the size of the trees at felling and the planting density.
Processing yields based on heartwood feedstock average 4% for katha and 8% for cutch.
Processing methods have been well defined in India and more recently have been re-examined in Thailand. Similarly, there is a substantial body of Indian silvicultural data on the species. Needs for future research on production relate mainly to definition of climatic limit constraints, particularly in the humid tropics.
The immediate developmental requirement is for a thorough market study which will define the opportunities or constraints for further expansion of production and trade.
As noted earlier, cutch is employed as a tanning agent for leather and in oil well drilling. Both crude and refined cutch and extracts of the tree bark have been traditionally used in medicine, usually as an astringent for treatment of sore throats and diarrhoea.
However, the primary demand for the tree in many growing sites is as a coppiceable fuelwood source. The timber is regarded highly, also, for furniture and implement manufacture.
The thorny branches are frequently employed for the construction of animal-proof hedges.
The tree is one of the hosts for lac insects.
KASHIO, M. (1992). Chemical Processing and Utilization of Acacia catechu Willd. Report no. RAPA 1992/19. Bangkok, Thailand: FAO Regional Office for Asia and Pacific.
AMATA-ARCHACHAI, P. and HELLUM, A.K. (1984). Seed collection of Acacia catechu Willd. Embryon. ASEAN-Canada Forest Tree Seed Centre, 1(1), 41-47.
LARSON, E. (1964). Germination response of Acacia seeds to boiling. Australian Forestry Research, 1(1), 51-53.
MISHRA, N.M. and SINGH, J. (1985). Local volume tables for Acacia catechu and Lannea Grandis. Indian Forester, 13(6),385-396.
RAINA, A.K. et al. (1990). Application of nutrients on growth of Acacia catechu in nursery bed. Indian Forester, 116(8), 655-662.
SINGH, S.P. and JAIN, R.C. (1987). Yield of heartwood in Acacia catechu (khair) for use in katha manufacture. Indian Forester, 113(6), 404-408.
SHAKYA, R. (1990). Plantation establishment pattern for community forestry plantations in the bhabar terai. Banko Janakeri, 2(4), 407-409.
SHARMA, R.P. (1981). Yield tables for Acacia catechu at various levels of stocking. Indian Forester, 107(9), 551-567.
SHERPA, S. et al. (1993). Interim report on silvicultural research trials. Dhankuta, Nepal: Pakhribas Agricultural Centre Working Paper No. 41 (19 pp.).
TEWARI, D.N. (1994). Biodiversity and Forest Genetic Resources. Dehra Dun, India: International Book Distributors (329 pp.).
TOKY, O.P. and BISHT, R.P. (1993). Above-ground and below-ground biomass in important fuelwood trees from arid north-western India. J. Arid Environments, 25(3), 315?320.
ALI, M.S. et al. (1992). Utilization of Acacia catechu leaves for dyeing textiles. Bangladesh J. Sci. Ind. Res., 27(3/4), 158-163.
AWASTI, A.K. (1982). Katha plant, a typical forest industry. Myforest, 18(1), 23-27.
DOBHAL, N.P. and BERI, R.M. (1981). A note on the katha content of Acacia catechu Willd. Growing in thick and open forests. Indian Forester, 107(4), 252-254.
FAO (1992). Chemical Processing and Utilization of Acacia catechu Willd (see Economics reference).
GUPTA, R. and AGARWAL, M. (1979). Katha production in the Terai areas of Uttar Pradesh. Proceedings of a Symposium on Production and Utilization of Forest Products, Jammu, India; Vol. 1, pp. 240-242. Jammu, India: Regional Research Laboratory.
JAIN, P.P. (1980). A note on the production of katha and cutch in India. Indian Forester, 106, 569-573.
KAMIS-AWANG and TAYLOR, D.A.; editors. (1993). Acacias for Rural, Industrial and Environmental Development. Proceedings of the Second Meeting of the Consultative Group for Research and Development of Acacias (CONGREDA), Udorn Thani, Thailand, Feb. 1993. Bangkok, Thailand: FAO Forestry Research Programme for Asia and the Pacific.
SHARMA, O.P. (1981). Chemistry and Technology of Katha and Cutch Manufacturing. Dehra Dun, India: International Book Distributors (303 pp.).
TEWARI, D.N. (1994). Tropical Forest Produce. Dehra Dun, India: International Book Distributors.
DECHATIWONGSE, T. and JEWVACHDAMRONGKUL, Y. (1986). Quality determination of catechus. Bull., Dept. Med. Sci., 28(1), 79-91.
DESHPANDE, V.H. and PATIL, A.D. (1981). Flavanoids of Acacia catechu heartwood. Indian J. Chem., 20B, 628.
INDIAN STANDARDS INSTITUTION. (1964). Indian Standards Methods of Sampling and Test for Katha, IS: 2962-1964. New Delhi, India: Indian Standards Institution.
INDIAN STANDARDS INSTITUTION. (1967). Indian Standard Specification for Cutch, IS: 3967-1967. New Delhi, India: Indian Standards Institution.
INDIAN STANDARDS INSTITUTION. (1967). Indian Standard Specification for Katha, IS: 4359-1967. New Delhi, India: Indian Standards Institution.
INDIAN STANDARDS INSTITUTION. (1969). Indian Standard Methods of Test for Vegetable Tanning Materials, IS: 5466-1969. New Delhi, India: Indian Standards Institution.
BOAZ, A.A. and BOAZ, O. (1994). The forest infanticide - a case study of the removal of brushwood from the forests of Naoradehi Sanctuary (Madhya Pradesh). Indian Forester, 120(1), 35-39.
JAIN, S.K. (1979). Utilization of indigenous tanning materials in leather with special reference to cutch. Proceedings of a Symposium on Production and Utilization of Forest Products; Jammu, March 1979. Vol. 1, pp. 217-219. Jammu, India: Regional Research Laboratory.
RAJARAM, N. and JANARDHANAN, K. (1991). Studies on under-exploited tree pulses, Acacia catechu, Parkinsonia aculeata and Prosopsis chilensis. Food Chemistry, 42(3), 265?273.
SHULKA, K.S. et al. (1985). Development of hardboards from spent chips of Acacia catechu. Indian Forester, 111(5), 339-344.
WITHINGTON, D. et al., editors (1988). Multipurpose Tree Species for Small-Farm Use. Proceedings of an International Workshop held November 1987 in Pattaya, Thailand. Co-published by IRDC and Winrock International Institute for Agricultural Development.
|Red dyestuff for textiles and paper.||Textile dyeing and wood staining (in Asia).|
|(a) Wood||Brazilwood; Nicaragua wood; brasilette; Lima wood; Pernambuco wood; Bahia wood.||Sappanwood; Indian redwood; kayu secang (Indonesia); sibukoa, sapang (the Philippines); sepang (Malaysia); teing-yet (Myanmar); faang (Thailand); vang nhuom (Viet Nam).|
|(b) Extract||Brazilin; brazilein.|
|Raw material source:||Heartwood of wild trees.||Heartwood of wild and cultivated trees.|
|Botanical source:||Haematoxylin brasiletto Karst.; Caesalpinia echinata Lam.; C. brasilensis L. (all in Leguminosae family) and some other species native to Central and South America.||Caesalpinia sappan L. (syn. Biancaea sappan (L.) Todaro (Leguminosae family) with distribution from India through Southeast Asia.|
|Product traded internationally:||Heartwood.||Heartwood.|
|World production and trade:||Data unavailable; probably very small current trade.|
|Availability of reliable published information:||Poor.||Fair.|
"Brazilwood" held the role as one of the most important red dyestuffs for textiles from the Middle Ages to the end of the nineteenth century. The name is derived from "fiery red" or "glowing coals". It was obtained originally from the heartwood of Caesalpinia sappan L., a small tree which occurs in India, across Southeast Asia and southern China. On the discovery of the Americas, several other tree species were found to provide a superior red dye and these rapidly displaced the East Indian product in trade, usurping the name of "brazilwood". The country, Brazil, acquired its name through the abundance of its redwoods rather than vice versa.
The American brazilwoods have been sourced from a number of different
countries and species over the years. Their precise botanical identities
and relative importance in trade have been the subject of debate. Record
and Hess (1943) state that at that time the major source was Haematoxylon
brasiletto Karst from Nicaragua. This species is a small tree with
a natural range from southern California to Colombia and Venezuela and
it overlaps with logwood (H. campechianum, the source of the black-blue
dye of commerce). The other main species frequently cited as major sources
of brazilwood are Caesalpinia echinata Lam. [syn. Guilandina
echinata (Lam.) Spreng] and C. brasilensis L. [syn. Brasiletta
violacea (Mill.) Britt and Rose] but according to Record and Hess,
these are native to Brazil and Haiti, respectively, and were never as important
as H. brasiletto. Additional minor sources include Caesalpinia
platyloba S. Wats [syn. Brasiletta platyloba (S. Wats) Britt
and Rose], C. bahamensis Lam. and C. andreana Mich.
The American brazilwoods contain a water-soluble compound, brazilin, in
their pale yellow heartwoods and this transforms on oxidation to the red
dyestuff, brazilein. Shades of purple to bright red are obtained according
to the mordant used in the dyeing process. East Indian sappanwood contains
brazilin and another pigment, sappanin.
International demand for East Indian sappanwood as a dye source declined to insignificance by the end of the nineteenth century. Imports of "brazilwood" from Central and South America to the USA and Western Europe appear to have declined after the 1950s and the extent of current trade is not clear from trade statistics.
Production of sappanwood for dyestuff purposes in India and Southeast Asia is now minor and incidental to other uses, which include fuelwood.
There appears to be little prospect of resurrecting demand for brazilwood
or sappanwood as dyestuffs, other than in small-scale, local artisanal
Climate and Soil Requirements
The "brazilwoods" of Central and South America span a range of ecoclimatic conditions but the requirements for individual species are less than adequately documented owing to some confusion in their identities.
East Indian sappanwood occurs at low to medium altitudes in India and Southeast Asia with rainfall ranging from 700-4,300 mm and mean temperatures of 24-28?C. It is adaptable to clay soil and calcerous rocks but does not tolerate waterlogging.
Little published information is available on the brazilwoods.
Sappanwood is propagated from seed, which benefits from immersion in boiling water. Cultivation is usually practised under the shade of other trees within the forest or on the forest verge and with a coppicing regime. For firewood use, coppicing is practised at intervals of 3-4 years while for dye production harvesting is carried out at 6-8 years when good heartwood formation has occurred.
For all species, the highest yields of dye are obtained by extraction of the heartwood. Heartwood is reduced to chips prior to sequential extraction in boiling water. With sappanwood, the raw material is often first reduced to a powder, moistened and is then allowed to ferment, thereby encouraging oxidation of the brazilin and the other natural pigments. The aqueous extract is concentrated prior to use as a dye. The yield of sappanwood dye has been reported as up to 20% of the heartwood on a moisture-free basis.
The American Caesalpinia species are described as hard and heavy timbers which are useful for construction work, pit props, etc., and find use in carpentry.
East Indian sappanwood is used in the Philippines as a fast growing coppiceable fuelwood. Elsewhere in Southeast Asia, it is frequently employed as a hedge while wood and bark are used in traditional medicine for the treatment of diarrhoea and a variety of other ailments. The fruits, like those of most Caesalpinia species, are rich in tannins and may be used for treatment of leather.
In view of the superiority, availability and price of competing synthetic dyestuffs, it is probable that brazilwood and sappanwood dye usage will be restricted to craftwork products in future.
With sappanwood, research is merited on its comparative value with other
species as a fast growing fuelwood source and on some aspects of its silviculture.
Its potential as a medicinal plant beyond existing, local traditional uses
RHANGAL GALINDO, R. (1949). Some industrial woods of Colombia. Caribbean Forester, 10(July), 179-180.
RECORD, S.J. and HESS, R.W. (1943). Timbers of the New World, New Haven, USA: Yale University Press.
ROBINSON, R. (1958). Chemistry of brazilin and haematoxylin. Bull. Soc. Chim. France, 1(Jan), 125-134.
DUKE, J.A. (1981). Handbook of Legumes of World Economic Importance. New York: Plenum Press.
FUKE, C. et al. (1985). Two aromatic compounds related to brazilin from Caesalpina sappan. Phytochemistry,24(10), 2403-2406.
LEMMENS, R.H.M.J. and WULIJARNI-SOETJIPTO, N. (1991). Plant Resources of Southeast Asia No. 3: Dye and Tannin Producing Plants. Wageningen, the Netherlands: Pudoc/Prosea.
SERRANO, R.C. (1984). Sibukao, excellent firewood. PCARRD Monitor (Los Banos, the Philippines), 12(6/7), 9-10.
TEWARI, D.N. (1994). Tropical Forest Produce. Dehra Dun, India: International Book Distributors.
ZERRUDO, J.V. (1985). Sibukao, a multi-purpose tree. Diamond Jubilee
Professorial Lecture, University of the Philippines, Los Banos (23
|Usage:||Orange-yellow dye for textiles.|
|Product synonym:||Kamala powder (English) rottlière des teinturiers (French) croton tinctoria(French)|
|Raw material source:||Fruits of a tree; mainly harvested from the wild.|
|Botanical source:||Mallotus philippensis (Lamk) Muell. Arg.; syn. Croton philippense Lamk. (Family: Euphorbiaceae).|
|Common synonyms for botanical source:||Kamala or monkey face tree; kapasan (Indonesia); banato (the Philippines); hpawng-awn (Myanmar); kaai kat hin (Thailand); rum noa (Viet Nam).|
|Distribution:||Western Himalayas, India, Southeast Asia, Southern China, through to Australia.|
|Availability of reliable published information:||Fair.|
The kamala tree (Mallotus philippensis Muell. Arg.) is an evergreen tree, growing up to 25 m which is indigenous to much of South and Southeast Asia and extends through the Pacific as far as Australia.
The fruit of the tree has a red glandular pubescence which, when detached
and comminuted, is known as kamala powder. The pigments, present at about
10% by weight, are partially soluble in hot water and are fully soluble
in organic solvents and alkalis. The principal red pigment is the chromene
compound, rottlerin which is somewhat unstable. On dyeing textiles such
as silk and wool, kamala powder produces an attractive bright orange colour
but this gradually fades on exposure to the sun.
Prior to the advent of colour-fast, synthetic dyes, kamala powder was used extensively in India and neighbouring Southeast Asian countries and enjoyed a small export trade. Today, usage has declined to a minor level within the region and demand can be met adequately from the harvesting of wild trees.
Some recent publications have suggested the possibility of employing
kamala as a colourant and as an anti-oxidant additive for processed foods.
However, the prospects are not good in such applications owing to a combination
of factors: the known physiological action of rottlerin (see later), the
costs of full toxicological testing and in the case of anti-oxidant applications,
the effective dosage probably would be very high.
Climate, Soil and Ecology
The kamala tree has a fairly wide adaptation range in the tropics and sub-tropics, displaying frost and drought resistance. In the wild state, it is most commonly found in evergreen forests but occurs also in scrub and on open rocky land. Kamala is frequently the pioneer tree in secondary forests in India where eventually sal (Shorea robusta) becomes dominant. It is shade tolerant.
Multiplication can be achieved by the use of root suckers or from seed. The latter are viable for approximately six months but the germination rate can be poor.
The tree grows slowly and often does not attain a trunk diameter of 15 cm after 15 years in India. Weeding in the early years is an important activity.
In India, harvesting is carried out as the fruits ripen in February and March and processing follows immediately. The operation involves detachment of the pigmented glandular pubescence on the fruits. Beating the fruit, followed by manual sifting provides the crude powder. Alternatively, the fruits may be stirred in water and the kamala powder which settles at the base of the vessel is recovered and dried. The yield of powder ranges between 1.5 to 4% of the fresh fruit weight. Crystalline rottlerin may be prepared by organic solvent extraction and concentration.
Rottlerin, the major pigment of kamala powder, has anthelmintic activity and extracts have been employed in India for treatment of cattle. It is reported also to reduce fertility in mammals.
The fruit seeds contain about 20% of a "drying oil", similar in properties to tung oil (Aleurites spp.), which has kamolenic acid as its major component. In India, the oil is employed as a fixative for cosmetics and to treat parasite infections on the skin.
The wood is often used as a fuel and occasionally as timber, but in this application suffers from a tendency to shrinkage and from insect attacks.
The leaves of the tree can be used as animal fodder.
The potential for greater utilization of the kamala tree does not appear
high, particularly in the context of formal cultivation. Prospects of increased
usage of kamala powder as a dyestuff or food colourant/antioxidant are
slim for the reasons described earlier. In the case of the seed oil, it
is necessary to study more thoroughly the economics of production and the
comparative advantage in its properties against other fatty oils derived
from faster growing species. It is possible that the kamala tree's economic
role will remain as a small source of seasonal income from the management
of wild forests.
GUPTA, O.P. and SHUKLA, R.P. (1991). The composition and dynamics of associated plant communities of sal plantations. Tropical Ecology, 32(2), 296-309.
JOSHI, A.P. and GUPTA, S.K. (1985). Mallotus philippensis in Garhwal Himalaya: an ecological account. Indian J. Forestry, 8(2), 134-136.
SINGHAL, R.M. and SHARMA, S.D. (1989). Phytosociological analysis of tropical forests in Doon Valley of Uttar Pradesh. J. Trop. Forestry, 5(1), 57-65.
SHUKLA, R.P. and PANDEY, U.N. (1991). On the reproductive phenology and sex ratio of Mallotus philippensis. Current Science, 61(5), 354-356.
BRINGI, N.V. (1988). Progress in the chemistry and technology of non-traditional oilseeds. J. Oil Technologists Assoc. India, 20(1), 2-9.
LEMMENS, R.H.M.J. and WULIJARI-SOETJIPTO, N., editors. (1991). Plant Resources of Southeast Asia No. 3: Dye and Tannin Producing Plants. Wageningen, Holland: Pudoc/Prosea.
TEWARI, D.N. (1994). Tropical Forest Produce. Dehra Dun, India: International Book Distributors.
BENTLEY, K. (1960). The Natural Pigments. New York: Interscience.
CROMBIE, L. et al. (1968). Constituents of kamala: isolation and structure of two new components. J. Chem. Soc., C, 265.
DEAN, F.M. (1963). Naturally Occurring Oxygen Ring Compounds. London: Butterworths.
GUJRAL, M. et al. (1960). Oral contraceptives. Pt. I. Preliminary observations on the antifertility effect of some indigenous drugs. Indian J. Medical Research, 48, 46-51.
SALUNKE, D.K. and ADSULE, R.N. (1985). Use of plants to control human
fertility. Current Research Reporter, 1(2), 113-117.