Abstract

Root system of tropical plants varies greatly in their form. A wide variation is observed in the distribution of root length, dominance of main roots, relative dimensions the number of root systems and their branching pattern. When grown in soil, thespatial orientation of root members is of considerable importance and the orientation of root axes determines the ability of the root system to retain the plant in an upright position. Besides, the extent of root spread should be taken into considerationwhen silvicultural operations are carried out. Quantitative information on root morphology is important in the study of soil ecosystem. Three species C.thwaitessi, C.pseudotenuis and C.rotang were investigated. In all the species studied, the germinationof the seeds was of adjacent ligular type. The growth of primary root stopped about four months after germination and subsequently more roots were produced from the basal portion of the plant. These roots produced the first and second order laterals after about 5 months. The initial growth was almost similar for all the species studied. The genneral morphology and developmental pattern were similar for C.rotang and C.Thwaitesii. Even though the shoot of the rattan remained in the rosette stage, the biomass increased because the basal portion of the plant increased in diameter until the potential maximum diameter for the particular species was reached. Hence it is concluded that methods which help to speed up the vegetative growth will shorten the period of the rosette stage. Rhizome production in all the species of rattans studied began only after the primary shoot reached its potential maximum diameter, characteristic of the species. Each new shoot developed from an axillary bud located near the baseof the stem