Abstract:
Pithecellobium saman (Leguminosae: cenizero) is one of several species of Costa Rican
deciduous forest large trees that flower at the end of the dry season and then bear dormant
tiny fruits through the following rainy season, to then abruptly enlarge and mature them during
the first third of the next year's dry season. I postulate that this pattern of fruit development
in P. saman minimizes the duration of exposure of immature seeds to parrot and insect seed
predators, increases the tree's flexibility in the use of photosynthates accumulated for later
fruit maturation, increases resource storage costs, and decreases the photosynthetic contribution
that fruit and immature seeds can make to the parent tree's resource budget. These consequences
imply that the fruiting phenology of P. saman, like that of other trees, is evolutionarily determined
by its interactions with the habitat as well as by internal physiological factors.
