A detailed study of growth behavior has been carried out on several species in Costa Rica by T. Ray (Harvard University). Only the general aspects of growth behavior will be reported here. Juvenile plants of a species of Syngonium are often extremely abundant, but there seems to be no correlation between the abundance of seedlings and the abundance of adults. In some cases adults are frequent and in other cases they are rare.

After germination of the seed, which is always in the soil, the plant remains in a rosette stage for a considerable time, the stem being slender with very short internodes. Leaves, at first ovate, are soon at least weakly lobed at the base. (A discussion of leaf development has already been made under the section on leaves.) Later (at least in some species), the stem elongates rapidly and growth is skototropic (Strong & Ray, 1975), i.e., the stem grows toward the darkest area available. Stem diameter may initially be only a few millimeters in this creeping phase, but internodes are elongate and leaves are much reduced. After the stem reaches a tree, it switches its physiology dramatically and begins to grow up the trunk toward the light. The stem continues up the trunk with relatively elongate internodes but also grows in girth and produces larger leaves. At this stage, the leaves (depending on the section) take on a different form. For example, climbing leaves of section Syngonium become sagittate or hastate. As the stem climbs, it becomes larger in girth and produces larger leaves and often stems with shorter internodes. Ultimately the plant produces adult foliage, which, depending on the species, can continue to be modified as the plant gets older or bigger. For example, pedatisect species tend to add more leaflets as they get larger.
All species of Syngonium are climbers and generally hemiepiphytic, though plants may survive with all apparent connections to the ground severed. Older plants particularly have good development of an adventitious root system, which can trap both water and nutrients.

Though it has fewer growth forms than Monstera, described by Madison (1977), the genus Syngonium has a wide range of variation in growth form. In general, the larger the stem of the adult plant, the shorter will be its internodes at time of flowering. The stem diameter of all species ranges from 1.7 cm at the smallest extreme to 2.3 cm at the largest extreme. Species with very slender stems tend to occupy disturbed habitats such as fence rows, and they tend to flower readily and frequently but generally produce fewer than 3 inflorescences. For example, species with stem diameters averaging about 1.5 cm in diameter produce an average of 3 inflorescences per axil, whereas species with stem diameters averaging 3.8 cm have an average of 4.8 inflorescences per axil. There are notable exceptions, such as S. angustatum with stem diameters of up to only 1.5 cm but with usually up to 7 inflorescences per axil. At the other extreme are such species as S. occidentale with stem diameters to 3 cm but only a solitary inflorescence per axil, and S. sagittatum with stem diameters to 4 cm and up to 3 inflorescences.

Internode length at flowering time is often very great, sometimes exceeding 12 cm. Some species such as S. laterinervium tend to branch readily and festoon the plant upon which they are growing. Species with stout stems, such as S. schottianum and S. macrophyllum, are frequent only in large trees and tend to flower less frequently but generally produce more inflorescences. Adults of such species are generally rarer, perhaps being capable of maturing only in trees of certain height. Certainly, such species are never capable of reaching maturity on or near the ground.

Most species of Syngonium have medium-sized stems and though their internodes are somewhat shortened at flowering time, they continue to elongate rapidly so that a considerable distance exists between a mature infructescence and a new inflorescence.

The genus Syngonium goes through modifications in its growth much like those in Monstera (Madison, 1977). Most species rarely branch except when a plant is damaged or when it outgrows its support and begins to fall. When the stem of an adult plant begins to droop from its support, it changes its growth habits to produce narrower, longer internodes and smaller leaves. This, of course, allows the plant to put more of its growth into elongation in order to more quickly reach a new source of support. Once the new support has been found by creeping across the forest floor, the stem begins to climb once more and again modifies its growth to produce a succession of intermediate pre-adult leaves and adult leaves. The pattern can be repeated endlessly.