Gutta-Percha-Yielding Plants

plants capable of accumulating the hydrocarbon gutta in special cell receptacles during their metabolic activity. Of most commercial significance in the tropical zone are trees of the genera Palaquium, Payena, and Bassia and of the family Sapota-ceae, which grow in virgin forests and plantations of some countries in Southeast Asia, New Guinea, and Egypt. Some species of the families Apocynaceae, Asclepiadaceae, and Euphorbiaceae and other forms of the flora of the hot countries of Asia, Africa, and Australia contain small quantities of gutta. Tropical gutta-percha-yielding plants have un-articulated but segmented elongated lacteals in the cortex of axial organs and in leaf tissues. Gutta accumulates in the lacteals in the form of a juice (latex) mixed with resins and some sugars, protein, and mineral salts.

In the USSR, the main gutta-percha-yielding plants are certain species of Euonymus and Eucommia (Eucommia ul-moides). The dry bark of Euonymus verrucosa roots contains 8–13 percent gutta on the average, and E. europaeus and E. latifolia contain about 7 percent. A substantial amount of gutta (2.5–21 percent) also accumulates in the cortex of E. maackii, E. miniatus, and E. macropterus roots. These shrubs grow in mixed deciduous forests on mountain slopes and in river valleys of the Far East. Eucommia is found in the central mountainous regions of China and in mixed subtropical deciduous and evergreen forests. Eucommia gutta is contained in elongated lacteals situated in the leaves along the veins and in the cortex in parenchymatous tissue. Dry leaves contain 3–5 percent gutta, trunk and branch cortex contain 3–6 percent, and root cortex and fruit contain 7–14 percent. It is used as a medicinal plant.