Llewelyn Williams

Laticiferous plants of economic importance II

The genus Cnidoscolus, of the Spurge Family (Euphorbiaceae), is a homogeneous group of herbs. shrubs or small to medium-sized trees indigenous to tropical America, with a few species extending to subtropical and temperate regions. The generic name, derived from the Greek meaning nettle and spine, alludes to the painfully stinging hairs frequently present. Two species of chilte growing in west-central Mexico are now utilized in industry as a source of gutta-like material with high hydrocarbon and resin content.

Laticiferous plants of economic importance: I. Sources of balata, chicle, guttapercha and allied guttas

Gutta-gums figure prominently in international trade. For more than 100 years the United States has been, and continues to be, the principal cousumer of these raw materials. Trade reports issued by the U. S. Department of Commerce indicate that during 1960 approximately 11,717,000 pounds of these forest products, with an aggregate value of

Laticiferous plants of economic importance IV jelutong (Dyera spp.)

6,536,792, were imported, mostly from Malaysia, Central America, and northern South America. These commodities are still furnished mainly by “wild” trees.Plantation development has been limited to small-scale propagation of guttapercha (Palaquium gutta Burck) in Indonesia and Malaya and recently of chilte (Cnidoscolus spp.) in western Mexico. In comparison with Hevea brasiliensis (Willd. ex Adr. Juss.) Muell. Arg., Castilla elastica Cerv., and other species of rubber, relatively little has been published on the sources of gutta-gums.

Laticiferous plants of economic importance V. Resources of gutta-percha-Palaquium species (Sapotaceae)

Trees ofDyera, a small genus of the Apocynaceae, are characteristic of the rain forests in western Malaysia. The raw product prepared from the coagulated latex was formerly used in Malaya and elsewhere as an admixture with guttapercha(Palaquium spp.) and later as a substitute forHevea rubber for purposes not requiring elasticity. During the past 50 years, trees of the 2 species of this genus hare been the principal source in southeast Asia of a gutta-gum, exported in appreciable quantities to Europe and particularly to the United States.

Laticiferous plants of economic importance III. Couma species

SummaryThe term gutta-percha is usually applied to the product of the tree classified asPalaquium Gutta (Hook.) Baillon, of the Sapodilla family (Sapotaceae). The genusPalaquium is represented by more than 100 species of medium-sized to large trees, widely distributed from India and Ceylon to New Guinea and adjacent islands in southeast Pacific.Gutta-percha fromP. Gutta was the first gutta-gum to become known in international trade, and has been used industrially for more than 100 years. As the source of supply diminished certain other species ofPalaquium trees, furnishing an inferior grade of gutta, came into production.Originally the method of extracting the latex was by felling the trees and girdling the trunk and main branches. Later, tapping of standing trees was enforced. Nowadays, most of the output is by mechanical or chemical treatment of plantation-grown leaves, and the product is of superior quality.Gutta-percha has long been esteemed for its insulating property, as a non-conductor of heat and electricity, and for its imperviousness to water, although its present-day consumption is on a much smaller scale than in former years. Its greatest use has been to cover submarine cables. Other uses include the manufacture of transmission belts, golf balls, in dentures, and for acid-resistant receptacles.

Natural Wealth of Tropical American Forests

The commercial use of the exudation of several species of Couma as a source of gutta-gum is of recent development. Although the edible fruits have been known in the Amazon basin since prehistoric time, and the coagulated latex, or coagulum, is favored by the South American Indian for caulking dugouts and canoes, the utilization of this gutta-gum in industry, especially in the United States, began only about 30 years ago.

South Brazil: Its vegetation, natural resources, research centers, and other economic aspects

The forest is a vast storehouse of wealth, not only in the form of wood, but also of a wide variety of other commercial materials of major or minor importance. W\e are apt to regard wood as the sole product of the tree and ignore other products or consider them secondary even though they play an important role in commerce. This is true of temperate forests and is particularly applicable to those of tropical regions. The bullet-tree (Manilkara bidentata [A. DC.] A. Chev.) of the Guianas and lower Amazon, for example, furnishes a timber suitable for heavy durable construction, while its bark yields a latex of still greater value as the source of balata utilized in the manufacture of transmission belts, golf-balls, and dentures. In British Guiana, balata extraction has been a foremost industry, for many years classed as the third most important of the country in volume of exports, with approximately 700,000 pounds shipped in 1959, mostly to England. Like Europe for centuries, the United States has been an importer of tropical forest products since Colonial days. Throughout the years, the consumption of these materials has been tremendous and continues undiminished. Despite the lack of a conservative, rational utilization, tropical forests continue to pour out a great tide of goods essential to the economy of certain nations. Their products may be laticiferous exudates, exemplified by rubber and allied elastomers; soluble gums and resins; essential and other oils; waxes; edible fruits; vegetable ivory; raw sources of fibers, pulp, lignin,

Forest and agricultural resources of Dahomey, West Africa

Although the five southern coastal states constitute only about 11% of the total area of Brazil, the core of the country’s agricultural activities, the principal commercial centers, and a high proportion of the population are concentrated within their boundaries. This article discusses the vegetation, some of the research institutions, agricultural and forest crops, and other economic features of those states.

The society for economic botany

Dahomey gained its autonomy in 1960. The abrupt changeover from the status of a colony to that of an independent nation naturally created problems and difficulties, affecting, in particular, the countrys agricultural pattemn. Dahomeys revenue has always been based almost entirely on the export of agricultural crops, especially palm kernels and palm oil (Elaeis guineensis Jacq.), peanuts, and karite or shea-nuts (Butyrospermum parkii Kotschy). During the past 8 years the total volume of imported foodstuffs, chiefly rice and cane sugar, has exceeded the value of exports, fluctuating each year between

News of the society for economic botany: Annual meeting in columbus, Ohio Preliminary announcement

10 and 20 millions (U.S.). To counteract this unfavorable trade balance, the immediate need of this developing country is the expansion of industrial or cash crops for export. Dahomeys current five-year plan, which started in 1966, gives high priority to the development of plantings of oil palm, cotton and peanut, rice and sugar production, the continuation of forestry and livestock development, and an increased production of food crops for domestic needs. Other projects being developed, or under consideration, are agriculture extension and education, animal husbandry, rinderpest eradication, promotion of the use of fertilizers and pesticides, improvement of agricultural cooperatives, and the establishment of pilot villages. In response to Dahomeys request for assistance in evaluating and developing its agricultural program, the United States Agency for International Development (AID) approached the International Agricultural Development Service (IADS) of the Department of Agriculture to make a survey of the countrys agricultural sector. The team of five specialists, including the author,