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.
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.
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.
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.
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.
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.