We studied the allometry and life history of an understory palm Pinanga coronata (Arecaceae) in a tropical montane rainforest on Mount Halimun, West Java, Indonesia. When the palm was small, the diameter of the stem increased with the minimum amount of vertical growth needed for new leaves to emerge (juvenile stage). After the base diameter of the stem and the length of the leaves reached a sufficient size (3.5 cm and 207.7 cm, respectively), the palm started to elongate the stem vertically (adult stage). The total mass and area of leaves in the crown increased with increasing stem mass, and approached constant values asymptotically. At the adult stage, the palm increased specific gravity of the lower part of the stem as it grew taller to support the increasing mass of crown and stem. To avoid self‐shading, crown architecture changed as the plant grew larger; leaf blades became longer and narrower and petiole length increased to display leaves efficiently away from the stem. The palm also produced clonal sprouting shoots and formed small clumps. Each clump contained an average of 7.5 shoots. The spatial distribution of the palm was strongly affected by topography, but only minimally affected by light conditions. The architectural adaptation to shaded conditions, effective dispersal of fruits and clonal growth are likely to be the factors that allow P. coronata to be one of the most dominant understory plant species in the study area.

Phenological changes in leaf production, leaf fall and inflorescence production of an understory palm, Pinanga coronata (Arecaceae), in a tropical montane rainforest on Mount Halimun, West Java, Indonesia, were observed monthly for a period of 17 months (November 1998 to March 2000. Meteorological data indicated that there were yearly dry (June to September) and wet seasons (October to May), and that the air temperature varied little through the year. Leaf turnover rate (average leaf production and fall rates) decreased during the dry period. However inflorescence production was continuous rather than seasonal. The number of leaves in a crown was nearly constant throughout the study period. Adult shoots that produced more leaves produced more inflorescences. Leaf production rate of P. coronata is sensitive to water availability. Therefore, water is one of the significant resources for growth of P. coronata.