Changes

*''Payena'' ''croixiana'' Pierre (1885), *''Madhuca'' ''leerii'' (Teijsm. & Binnend.) Merr. (1923).

''P. leerii'' is found in Peninsular Malaysia, Sumatra, the Riau Archipelago, Bangka, Borneo and the southern Philippines (Palawan, Mindanao, Sulu Archipelago); it is cultivated in Java, and rarely also in tropical Africa and South America.

The gutta-percha from ''P. leerii'' is of good quality and is used similarly to that of ''Palaquium gutta'' (Hook.f.) Baill. It has been used extensively for submarine and underground cables due to its non-conductivity for electricity and heat, and its imperviousness to water. Golf balls used to be manufactured with an outer cover of gutta-percha. It has also been used for medical and chemical instruments, in dental clinics, transmission belts, acid-resistant receptacles, as adhesives, waterproofing agent and an ingredient of chewing gum. The advent of synthetic resins and other petroleum-based polymeric materials led to the rapid decline in 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 tools in their handles. In South Sumatra the gutta-percha from ''P. leerii'' is known as "getah sontik", in South Kalimantan as "getah beringing", and in Sarawak as "getah jangkar". The timber is used as "bitis", sometimes occasionally as "nyatoh". Bitis is a durable timber used for heavy constructional work, agricultural implements and for heavy-duty flooring, posts, and door and window frames. Nyatoh is a less durable timber when in contact with the ground; it is important for the manufacture of fine furniture, decorative doors and veneers and panelling. The fruits are edible and taste like sapodilla (''Manilkara zapota'' (L.) P.Royen), but have little pulp. == Production and international trade == Indonesia is probably the largest producer and exporter of gutta-percha. The annual exports were 3-366 t in 1988-1993, but these figures may not be reliable. In 1963-1972 the average annual import in the United States from Indonesia was 1140 t. The gutta-percha of ''Palaquium gutta'' and other ''Palaquium'' spp. is included in these figures, ''P. leerii'' probably only yields a small part of the gutta-percha traded. Early in the 20th Century the average annual world consumption of gutta-percha was 850 t, but an average annual export of 14 000 t from Singapore over the period 1900-1920 has also been reported. Export from Sarawak of "getah jangkar", the gutta-percha from ''P. leerii'', ''Madhuca motleyana'' (de Vriese) J.F.Macbr. and ''Pouteria malaccensis'' (C.B.Clarke) Baehni, was 26-75 t annually in the period 1949-1953. "Bitis" timber is usually converted to scantling sizes, and sold unclassified. Although ''Madhuca utilis'' (Ridl.) H.J.Lam ex K.Heyne, ''Palaquium ridleyi'' King & Gamble and ''Palaquium stellatum'' King & Gamble are the main bitis-producing species, ''Payena leerii'' may also supply this type of timber. == Properties == As the latex of ''P. leerii'' is collected and not the coagulated product (as in the case of ''Palaquium'' spp.), the product contains less debris and is whiter than the "getah merah" from ''Palaquium gutta''. However, the gutta-percha from ''P. leerii'' becomes yellow when exposed. Raw gutta-percha from ''Payena'' spp., probably mainly ''P. leerii'', contains 14-26% water, 40-46% gutta, 30-32% resin and 3-8% foreign material; when purified it contains 54% gutta and 46% resin. The gutta-percha has a comparatively high plasticity and, unlike the large amount of resin it contains, is of good quality. The gutta-percha is not sticky, but rapidly changes with time, it then becomes brittle on the surface and sticky when heated. Some trees seem to yield a sticky gutta-percha and others yield a non-sticky gutta-percha. The timber is heavy with a density of 760-1060 kg/m³ at 15% moisture content. The heartwood is deep pink, red, red-brown or purple-brown, sometimes with dark streaks, distinctly to indistinctly demarcated from the pale red sapwood. The grain is shallowly to moderately interlocked, sometimes wavy and the texture moderately fine to slightly coarse. The seed contains 3.5-4.5% oil. == Description == *A medium-sized to fairly large tree up to 40 m tall, with columnar bole up to 80 cm in diameter, buttressed, containing white latex which turns yellow upon exposure; twigs slender and terete, usually hairy or scurfy.*Leaves alternate or arranged spirally, simple, entire; stipules 3-4 mm long, falling off early; petiole 0.5-1.5 cm long; blade broadly ovate to oblong-lanceolate, 5-16 cm × 1.5-8 cm, base cuneate to rounded, apex acuminate, glabrous on both sides; midrib sunken above and prominent below, secondary veins 11-18, straight, curving towards apex and joined near leaf margin, tertiary veins mostly descending from marginal conjunctions of secondary veins and ramifying into 2-3 branches which run parallel towards the midrib, tertiary vein just visible on lower leaf surface.*Inflorescence a small, axillary (sometimes pseudo-terminal) fascicle, 1-8-flowered, often in defoliate leaf-axils; pedicel 1-1.5 cm long.*Flowers bisexual, very small, up to 0.5 cm long, white to yellow-white; sepals 4, 2-4 mm long, 2 outer ones thick and fleshy, 2 inner ones thinner; corolla 8-lobed, 2 mm long, with short tube, glabrous, white or yellowish-white; stamens 16, inserted at the throat of the corolla tube, with short, pubescent filaments, acute anthers and long-ciliated connective; pistil 1, with long conoidal 8-celled ovary and persistent style, 6-8 mm long.*Fruit a berry, cone-shaped or narrowly so, with a flat broad base, 2.5-5 cm × 1-2.5 cm, glabrous or subglabrous, abruptly passing into the style at apex, usually 1-seeded, green.*Seedling with epigeal germination, hypocotyl elongated; cotyledons emergent; leaves alternate-spiral from the start. == Growth and development == In a plantation in West Java trees of ''P. leerii'' flower and fruit already at an age of about 7 years. Although the tree can be found flowering and fruiting year-round, major flowering time is April-August in Malesia. == Other botanical information == ''P. leerii'' is closely related to ''P. obscura'' Burck from which it can be distinguished by its conical fruit with an abrupt slender style and a rather flat broad base. Gutta-percha of ''P. dantung'' H.J.Lam has also been used; the product is more like rubber than like gutta-percha but, like gutta-percha, it becomes plastic when heated. == Ecology == ''P. leerii'' is most commonly found in primary forest, up to 1000 m altitude. == Propagation and planting == ''P. leerii'' can be propagated by seed; propagation by cuttings is possible but difficult. Seed loses its viability in 2(-8) weeks and should be sown in deep nursery beds, as the seedlings form a well-developed taproot. Young plants need shade and plenty of water. Planting should be done with great care, so as not to injure the taproot and to ensure that the taproot is straight when planted. Early in the 20th Century ''P. leerii'' was formerly important planted experimentally in Java, e.g. in the gutta-percha plantations in Cipetir, West Java; growth was very good, but tapping these trees gave only very low yields. The spacing applied was 2 m × 2 m. Planting has been tried in Singapore and Peninsular Malaysia but these trials were abandoned when wild supplies, which had escaped notice, were discovered. == Management == In young plantations of ''P. leerii'', ''Paraserianthes falcataria'' (L.) Nielsen is often used to provide shade. In the first 7-8 years after planting, weeding is necessary about 4 times per year, later only once a year. The canopy closes 10-12 years after planting when weeds are shaded out completely. The trees then reach 6-13 m in height. == Harvesting == In the bark of felled trees of ''P. leerii'' 1-1.5 cm wide rings are cut from which the latex exudes and is collected in containers placed underneath. The latex is more fluid than that of other ''Sapotaceae'' species which yield gutta-percha and does not (partially) coagulate during collection. The destructive method of collection had already been forbidden in several countries in the first half of the 20th Century, as resources were being rapidly depleted. Various methods for tapping the living trees have been developed, but yields are so low that ''P. leerii'' has never been tapped on an economic scale. ''Payena'' trees contain irregular latex cavities in the bark which are not connected, and tapping cannot be done repeatedly as in the case of para rubber (''Hevea brasiliensis'' (Willd. ex Juss.) Müll.Arg.). == Yield == The yield of gutta-perchaof ''P. leerii'' is generally low: only 60-270 g of gutta-percha could be obtained from felled trees of 17-26 cm in diameter. Tapping trials gave only 3-22 g of gutta-percha per tree. == Handling after harvest == The fruits latex of ''P. leerii'' is heated over a fire and stirred continuously until coagulation is complete. The coagulum is then pressed into blocks after first softening it in hot water and removing larger pieces of foreign matter. The blocks are ediblethen transported to the factory for further processing. The blocks can best be stored underwater to avoid spoilage by oxidation on exposure to air. Purified gutta-percha can be prepared by a chemical method which entails 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. The problem is that the natural anti-oxidants in the gutta-percha are also extracted, increasing susceptibility to deterioration through oxidation; however, chemical anti-oxidants may be added. The mechanical method involves processing the raw gutta-percha by treating it with hot water to remove impurities, and collecting and pressing it into blocks. The gutta-percha used to be adulterated with inferior gutta-percha, such as that from ''Palaquium leiocarpum'' Boerl. and low-quality gutta-percha from ''Palaquium gutta'' and with jelutong (''Dyera'' spp). == Genetic resources and breeding == Resources of ''P. leerii'' were already dwindling early in the 20th Century when destructive collection of latex was forbidden. As trees occur scattered in the natural forest, they are liable to genetic erosion due to logging. There are no known germplasm collections or breeding programmes for ''P. leerii''. == Prospects == Gutta-percha from ''P. leerii'' is not an important commodity. ''P. leerii'' is much more important as a timber-yielding tree. == Literature ==

A medium-sized to fairly large tree up to 40 m tall35, with columnar bole up to 80 cm in diameter36, buttressed; leaves broadly ovate to oblong-lanceolate100, glabrous on both sides; flowers very small102, up to 0.5 cm long255, white or yellowish-white; fruit cone-shaped or narrowly so315, with a flat broad base318, 2.5-5 cm long322, glabrous or subglabrous. ''P.'' ''leerii'' is closely related to ''P.'' ''obscura'' and is most commonly found in primary forests451, up to 1000 m altitude. The timber is usually heavy with a density of 760-1060 kg/m³at 15% moisture content. The gutta-percha is of good quality461, 486, 581, 727, 730, but the yield is generally low779.timbers

== Selected sources Authors ==

35, 36, 100, 102, 255, 315, 318, 322, 451, 461, 486, 581, 727, 730, 779*E.Boer