flowers (plate 3- 17) may facilitate pollination by
animals such as bats. Equally likely, cauliflorous
fruiting may facilitate dispersal of seeds from fruit
consumption by large, terrestrial animals that could
not reach canopy fruits.Leaf Characteristics
One feature of the Neotropics that you cannot miss is
leaves; from large to small, they are everywhere (plate
3- 18). Leaves of tropical tree species are surprisingly
similar in shape, which makes species identification
difficult (plate 3- 19). The distinctive lobing patterns
of many North American maples and oaks are
missing from most tropical trees. Instead, leaves are
characteristically oval, unlobed, and often possess
sharply pointed ends, called drip tips, that help facilitate
rapid runoff of rainwater (plate 3- 20). Leaves of most
species have smooth rather than toothed margins,
though serrate leaves are found in some species. Both
lowland and montane tropical forest trees produce
thick, leathery, and waxy leaves that can remain on the
tree for well over a year. Many tropical species produce
palmate compound leaves, in which the leaflets radiate
like spokes from a center, forming a shape similar to
that of a parasol. Some leaves, particularly those on
plants that are found in disturbed areas such as gaps,
are conspicuous for their large size, well in excess of
the leaves of any temperate- zone species. Though many
trees have simple leaves, compound leaves are common,
particularly due to the abundance of legumes, a highly
species- rich plant family.Plate 3- 18. The huge leaves on these plants growing in a
sunny gap in Ecuador are sufficiently large that they can be
used as umbrellas if it begins to rain. Photo by John Kricher.Plate 3- 20. This understory plant clearly shows drip tips.
Note that the leaves hang down, facilitating the flow of water
from the plant during heavy rain. Photo by John Kricher.Plate 3- 19. This selection of leaves from tropical trees
illustrates many of the basic leaf characteristics: drip tips,
waxy appearance, lack of complex lobing. Two of the six are
compound leaves. Photo by John Kricher.chapter 3 rain forest: the realm of the plants 45