Castilla elastica (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Castilla elastica Sessé

Protologue: Moraceae

Synonyms

• Castilla costaricana Liebm.,
• C. panamensis O.F.Cook,
• Ficus gummifera (Miq.) Miq.

Note: The erroneous genus name Castilloa sometimes occurs in the literature.

Vernacular names

• Mexican rubber (En)
• Philippines: castilloa rubber tree.

Distribution

C. elastica occurs naturally from Mexico through Panama to western Colombia and western Ecuador. Subsp. elastica occurs naturally from Mexico to north-western Costa Rica but has been introduced into many tropical areas; subsp. costaricana (Liebm.) C.C.Berg occurs naturally from Costa Rica to south-western Colombia and has been introduced in a few other countries, but is cultivated in Indonesia; subsp. gummifera (Miq.) C.C.Berg occurs naturally from Ecuador to south-western Colombia. C. elastica was introduced in Bogor in 1876.

Uses

The rubber, obtainable from the latex, can be used like para rubber. The latex from this tree was probably being processed into rubber as early as 1600 BC in Ancient Mesoamerica. Because quality and yield are less than from para rubber, there are no longer any commercial plantations.

Observations

• Monoecious or dioecious tree, up to 30 m tall with low buttresses, exuding white latex when wounded; twigs clothed with soft hairs, dimorphic, some falling off ("self pruning"), the persistent ones never producing flowers.
• Leaves pendulous, distichous on caducous twigs, arranged spirally on persistent twigs; stipules fully amplexicaul, connate, 2-12 cm long, yellow strigose, margins white-tomentellous; petiole 2(-10) cm long; blade ovate to oblong, 1540(-55) cm × 5-20(30) cm, base cordate, margin entire or shallowly dentate, apex acuminate, beneath with soft hairs and with about 20 pairs of prominent secondary veins, leaves on persistent twigs smaller than those on caducous twigs.
• Inflorescences capitate, peduncled, manyflowered, cupshaped; male heads 1-3 cm in diameter, often 4 together, on peduncle 1.5 mm long; female heads solitary, subsessile, smaller than male head.
• Male flowers without perianth, stamen 1; female flowers with ovoid perianth, 4-lobed, style 2-branched.
• Infructescence 35 cm in diameter, red to orange or pink, with pyramidal, hairy apex; fruit ellipsoidal, about 1 cm long.
• Seed brownish.

C. elastica is found in forests up to 850 m altitude, often along streams, in clearings, or at forest margins. Three subspecies have been distinguished on the basis of distribution pattern and indumentum type. C. elastica can be easily propagated by seed and by cuttings from the persistent branches. Many years after the plantations in Java had been cleared the plants were still producing shoots from coppice. In trials C. elastica grew faster than para rubber. Although there were fairly extensive plantations in Peninsular Malaysia and Central and East Java, the yield and the quality of the rubber proved to be inferior to para rubber. Moreover, in Peninsular Malaysia plantations were severely damaged and even destroyed by a number of diseases and pests and trees did not stand up to tapping very well. One litre latex yields about 200 g rubber. The mean annual rubber yield from trees in Java was 150 g.

Selected sources

2, 7, 8, 10, 11, 22, 23, 27, 40, 42.