Changes

* ''Palaquium calophyllum'' (Teijsm. & Binnend.) Pierre, Ann. Jard. bot. Buitenz. 5: 28 (1886), synonym: *''Isonandra calophylla'' Teijsm. & Binnend. (1864).

* ''Palaquium gutta'' (Hook.f.) Baill. - see separate article.

* ''Palaquium leiocarpum'' Boerl., Bull. Inst. bot. Buitenzorg 5: 24 (1900), synonyms: *''Palaquium molle'' Pierre (1902), *''Croixia leiocarpa'' (Boerl.) Baehni (1965).

* ''Palaquium luzoniense'' (Fern.-Vill.) S.Vidal, Revis. pl. vasc. Filip.: 176 (1886), synonyms: *''Palaquium ahernianum'' Merr. (1903), *''Croixia luzoniensis'' (Fern.-Vill.) Baehni (1965).

* ''Palaquium obovatum'' (Griff.) Engl., Bot. Jahrb. Syst. 12: 511 (1890), synonyms: *''Isonandra obovata'' Griff. (1854), *''Palaquium theoideum'' Elmer (1910; " ''theoidea'' ").

*General: *gutta-percha (also used for other ''Sapotaceae'' species whose latex is used), nyatoh, bitis.

* ''P. calophyllum'' : *Indonesia: nyatoh jankar merah, nyatoh tunjung, karikip (Kalimantan)

* ''P. leiocarpum'' : *Indonesia: jongkang, hangkang (Kalimantan)

''P. luzoniense'':* Philippines: kalipaya, nato (general), dolitan (Tagalog).  ''P. obovatum'' : *Indonesia: mayang katapong, balam terupuh (Sumatra), siki putih (Ambon)

Gutta-percha, the coagulated latex from the bark or leaves of several ''Sapotaceae'' species including ''Palaquium'' , has been used extensively for submarine and underground cables due to its non-conductivity for electricity and heat, and imperviousness to water. Golf balls used to be manufactured with an outer cover of gutta-percha. This was the only significant end-use in the 1960s and 1970s. It has also been used for medical and chemical instruments, in dentistry, transmission belts, acid-resistant receptacles, as adhesives, waterproofing agents and as an ingredient of chewing gum. The advent of synthetic resins and other petroleum-based polymeric materials led to the rapid decline in the use of the natural material. At present its main application is for protecting wounds and in dental clinics, where it is proving to be useful for people allergic to synthetic fillers. Locally the gutta-percha is used for fixing tool handles.

The timber of ''Palaquium'' is of major importance. Species are traded as "nyatoh" containing the lightweight to medium-weight ''Sapotaceae'' species (e.g. ''P. leiocarpum'' , ''P. luzoniense'' , ''P. obovatum'' ) or as "bitis" comprising the heavy hardwoods.

*Small to very large trees, with latex in all tissues, sometimes up to 60 m tall, usually with columnar buttressed bole up to 130(-250) cm in diameter, often branchless for a considerable length; outer bark smooth, cracked or fissured, usually brown to reddish-brown, inner bark soft and fibrous, pinkish-yellow, pink, red or reddish-brown; twigs usually slender, often hairy or scurfy at least at tips, often with distinctly developed terminal cone-like buds. *Leaves arranged spirally, usually densely to loosely clustered at ends of twigs; stipules small to large, usually early caducous, rarely absent; petiole usually of even thickness throughout its length; blade simple and entire, usually obovate, generally glabrous above and more or less hairy beneath when mature; secondary veins straight, curving towards apex and often joined near leaf margin, tertiary veins transverse or parallel to secondary ones or reticulate. *Inflorescence an axillary or rarely terminal fascicle, 1-many-flowered; flowers .*Flowers bisexual or rarely unisexual; sepals (4-)6(-7), generally in two whorls of 3, ovate or triangular; corolla (5-)6-lobed, with usually short tube and imbricate, often contort lobes, white to yellowish or greenish; stamens (10-)12-18(-36), inserted at the throat of the corolla tube, with acute anthers; pistil 1, with (5-)6(-10)-celled ovary and usually long style. *Fruit a berry with fleshy pericarp, 1-3-seeded. *Seed with a crustaceous to coriaceous testa and a large hilum often covering up to two-thirds of the surface of the seed; endosperm usually absent and cotyledons thick and fleshy. *Seedling usually with epigeal germination and strongly developed taproot; first pair of leaves opposite or subopposite, subsequent leaves arranged spirally and soon similar to leaves of adult trees.  ''P. calophyllum'':*a small tree up to 15 m tall.*Leaves evenly distributed, obovate, rarely elliptical, 3.5-9 cm × 7-19 cm, tomentose or velvety beneath, tertiary veins transverse to secondary ones.*Flowers in 2-11-flowered clusters; pedicel 10-25 mm long (in fruit up to 30 mm), rust- or golden-coloured tomentose.*Fruit depressed globose, 2 cm × 2.5 cm, densely red-brown tomentose.  ''P. leiocarpum'':*a small to fairly large tree up to 35 m tall.*Leaves evenly distributed or loosely clustered at tip of twigs, ovate, obovate or elliptical, 5-27 cm × 4-10 cm, with few transverse tertiary veins almost parallel to secondary veins and with a reticulate venation in between, velvety beneath.*Flowers whitish in 3-6-flowered clusters; pedicel 8-15 mm long (in fruit up to 30 mm).*Fruit globose to ellipsoidal, 15-25 mm long, glabrous.

* ''P. leiocarpumluzoniense'' : *a small to fairly large medium-sized tree up to 35 25 m tall; leaves evenly distributed or loosely , with bole up to 50 cm in diameter, but sometimes attaining 120 cm, lacking buttresses.*Leaves clustered at tip of twigs, ovate, obovate , oblong or elliptical, 511-27 20 cm × 42-10 cm, with few transverse tertiary veins almost parallel to secondary veins and with a reticulate tertiary venation in between, velvety minutely hairy beneath; flowers .*Flowers yellowish-green or whitish , in 31-64-flowered clusters; pedicel 8slender, 20-15 65 mm long (in fruit up to 30 mm); fruit globose to .*Fruit ellipsoidal, 153.5-25 mm 4 cm long, glabrousinitially minutely hairy but glabrescent, dull green.

* ''P. obovatum'' : *a medium-sized to large tree up to 45 m tall, with columnar bole up to 80(-110) cm in diameter; leaves .*Leaves usually densely clustered at tip of branches, obovate to oblong, 6-45 cm × 3-17 cm, with distinct, transverse tertiary venation, puberulous or glabrous and glaucous beneath; flowers .*Flowers greenish-yellow or greenish-white, in 4-12-flowered clusters; pedicel up to 2 cm long; fruit .*Fruit globose, ellipsoidal to obpyriform, 2-3 cm long, glabrous; germination hypogeal.

'''== Management''' == In Peninsular Malaysia early in the 20th Century 3000 ha of natural forest were transformed to almost pure gutta-percha forest (containing ''P. gutta'' and ''P. obovatum'' ). This type of forest management was abandoned in the 1960s.

Traditionally the latex is harvested by felling the tree, lopping off the branches and by cutting a number of rings in the bark at a spacing of 30-60(-100) cm. The exuding latex is collected in containers placed under the tree. This destructive method had already been abandoned in the first half of the 20th Century in several countries because resources had depleted rapidly. Various methods have been developed for tapping the living trees. Usually a series of V-shaped cuts 20-30 cm apart at an angle of 45°to the vertical are made and these cuts are joined by a vertical cut. The cuts are made on two sides of the tree, leaving a strip of untapped bark 10 cm wide. Most of the latex coagulates in the cuts and exuding latex is collected in a small cup attached to the bark. The coagulated latex is scraped off and formed into a ball, which is then pressed into the cuts and rolled along them. Each time the ball is rolled along a cut, the removal of the coagulated latex re-opens the cut ends of the latex cavities and the flow recommences. A rest period of at least 2 years was reported to be necessary before trees could be tapped again, to maintain the economic productivity. ''Palaquium'' trees contain irregular latex cavities in the bark which are not connected, so they cannot be tapped continuously like para rubber ( ''Hevea brasiliensis'' (Willd. ex Juss.) Müll.Arg.). Cloudy, moist conditions allow the latex to flow more easily than during hot, sunny periods, when there is some loss of water by evaporation. 

The latex of ''P. leiocarpum'' , which does not coagulate on the tree, is heated over a fire while stirred continuously until coagulation is completed and water has evaporated. Primary processing of other partially coagulated latex is done in a similar manner. The coagulum is then pressed into blocks after first softening it in hot water and removing larger pieces of foreign matter. The blocks are then transported to the factory for further processing. The blocks can best be stored under water, to avoid spoilage by aerial oxidation. In former days gutta-percha was deliberately adulterated with chopped bark, wood and even stones to increase its weight. Purified gutta-percha can be prepared by dissolving the resinous fraction in cold petroleum spirit, and then dissolving the remaining, separated gutta fraction in hot petroleum spirit. The hot extract is drained from any insoluble foreign matter and then allowed to cool, whereupon the purified gutta-percha separates out. After separation and distillation of residual solvent the hot, plasticized gutta is rolled into sheets and stored, either in the dark in well-sealed tins, or in water. This chemical method yields the "white gutta-percha", which has a resin content of 1% and hardly any foreign matter. The problem is that the natural anti-oxidants in the gutta-percha are also extracted, hence, the gutta-percha becomes susceptible to deterioration through oxidation. However, chemical anti-oxidants may be added. The mechanical method involves processing the raw gutta-percha by treatment with hot water to remove impurities, and collecting and pressing it into blocks. This yields "yellow gutta-percha" with about 9% resin and 3% impurities.