Hyeronima alchorneoides
Allemao
Common Name: PILON, ZAPATERO
Occasional evergreen canopy tree (30-35 m) distributed thinly
throughout the most humid primary forests, though avoiding the
immediate coastline. Pilon is an appreciated timber tree, yielding
strong and heavy wood for construction, however its ecological
role - providing forage to a wide variety of birds and mammals
- makes this tree more valuable left standing.
Description: Pilon has a stout (>1m),
cylindrical, and straight trunk that rises vertically to
the canopy layer before branching. There, the upwardly-angled
limbs give rise to a characteristically wide and hemispherical
crown, in which the foliage is confined to the outermost layer
of twigs. Buttresses, as such, are not present but large, rounded
roots (often over 30 cm in diameter) do emerge from the massive
bole just above the soil. These travel considerable distances
along the surface of the forest floor, tracing out snake-like,
meandering paths before disappearing from view. The bark is thick,
vertically fissured, and has a hallmark, rusty or burnt-orange
hue that is most notable within the deep grooves and near the
base of the tree. Moss is often found growing on the base of these
boles as well, seeming to prefer Pilon to other large species.
Uniquely colored, thick, blood-red sap lies underneath the bark
of boles, branches and twigs and is also found in the dark heartwood.
Leaves are simple and alternate, arranged in whorl-like
clusters around branch tips. Their most readily visible feature
is a long, grooved petiole (3-6 cm), possessing a marked, 
elbow-shaped
bend or crook just before the blade. Also unusual, the leaves
have a bicolored appearance thanks to a dense but fine covering
of tan pubescence on their lower surfaces, as well as on petioles
and twigs. Blades are widely elliptical in shape - sometimes nearly
orbicular - with prominent, pinnate venation and short drip tips.
Varying widely in size, leaf dimensions range from 13-22 cm in
length and 6-11 cm in width. Old leaves redden before falling
and the tree's green crown, mottled with patches of scarlet, is
an identifying characteristic for this species. Flowers
are imperfect, with male and female blossoms borne on different
trees (Pilon is dioecious). Both types of flowers grow from leaf
axils on large (7 cm), branched panicles. They are tiny (2 mm
in diameter), green, and petal-less, with only a few short stamens
(male) or vestigial staminate appendages (female) to adorn them.
Flowering periods are complex and bi-annual, with male trees blossoming
for much more extended periods than females. The main flowering
season for male trees begins in August and lasts through November,
while female trees are fertile only from late September through
October. Males resume flowering in February and continue through
early April, with females participating in late February. Fruits
are produced rapidly after the females flower. Each panicle supports
tens of small (3 mm - spherical drupes that ripen from green to
a deep red wine color. A single white seed (1.5 mm) is contained
within the juicy pulp. Harvests are also bi-annual and their intensity
varies from season to season. Each begins about six weeks after
flowering, the first lasting from December through January and
the second from mid-May through mid-June.
Similar Species: With its reddish-brown
trunk, great stature, nearly omnipresent male flowers, and large,
long-petioled leaves that turn red in the canopy, Pilon is relatively
easy to identify in the field. Other species with long-petioled,
elliptical leaves include Dendropanax arboreus and Capparis
discolor, however these are much smaller, understory or subcanopy
trees whose bark characteristics bear no resemblance to those
of Pilon.
Natural History: Pilon flowers are visited
by bees, wasps and other insects, seen swarming thickly around
the inflorescences on clear, sunny days. Fruits are much sought
after by local fauna - with both White-faced and Squirrel monkeys
included in this category. The monkeys often break the thin twigs
carrying both the fruit panicles and the leaf whorls, and the
discarded remnants of these branches frequently litter the ground
underneath fruiting Pilons. Birds, such as saltators, also forage
in Pilon trees during harvest.
Pilon trees demonstrate one of two opposing reproductive tendencies
in plants with their habit of fabricating huge quantities of small
fruits and seeds. In general, plants have a limited amount of
energy to invest in reproduction and so the number of seeds and
fruits that any species can form and disseminate is inversely
proportional to fruit size. Usually, a tree producing large seeds
(most often found inside large fruits) can only afford to make
a relatively small number of them. However, the larger seed also
means more stored food (most of a seed's mass is stored food -
the embryo represents only a tiny fraction of its total weight)
for the tiny seedling. Coming at a time when it is not able to
do much photosynthesis for itself, the presence of this energy
source enhances the seedling's chances of survival. Trees producing
mass quantities of small seeds forego this advantage. Typically,
their seedlings are still small and weak when food stores run
out. However, they compensate for this decreased chance of individual
seedling survival by drastically increasing the number of times
it is applied. Apparently, both of these reproductive strategies
are successful, since many trees of each type thrive in tropical
forests.
The apparent preference of mosses for Pilon bark can perhaps be
explained by its water-holding capacity. Porous, especially near
the tree's base, this thick bark can absorb much moisture. Deep
in the lower layers of the primary forest where there is no sunlight,
this bark stands little chance of drying out. Mosses, non-vascular
plants possessing no water-conserving cuticle over their exposed
tissues, need a constant supply of water in order to avoid desiccation.
The thick bark of Pilon trees can provide a steady and ample water
supply in a way that few other trees can.
Uses: Pilon is renown for its very heavy, coarse-grained, dark
maroon-colored wood that is used extensively in house construction.
Obviously, its importance to forest animals makes Pilon a vital
ecological component of the forests that it inhabits.
Distribution: In Costa Rica,
populations of this species have been located in Manuel Antonio,
Corcovado, the Isla del Caño, and Punta Leona. It ranges
from Mexico through Central America and into South America.
Flower Fruit Trunk Leaf Leaf
Description: Pilon has a stout (>1m),
cylindrical, and straight trunk that rises vertically to
the canopy layer before branching. There, the upwardly-angled
limbs give rise to a characteristically wide and hemispherical
crown, in which the foliage is confined to the outermost layer
of twigs. Buttresses, as such, are not present but large, rounded
roots (often over 30 cm in diameter) do emerge from the massive
bole just above the soil. These travel considerable distances
along the surface of the forest floor, tracing out snake-like,
meandering paths before disappearing from view. The bark is thick,
vertically fissured, and has a hallmark, rusty or burnt-orange
hue that is most notable within the deep grooves and near the
base of the tree. Moss is often found growing on the base of these
boles as well, seeming to prefer Pilon to other large species.
Uniquely colored, thick, blood-red sap lies underneath the bark
of boles, branches and twigs and is also found in the dark heartwood.
Leaves are simple and alternate, arranged in whorl-like
clusters around branch tips. Their most readily visible feature
is a long, grooved petiole (3-6 cm), possessing a marked, 
elbow-shaped
bend or crook just before the blade. Also unusual, the leaves
have a bicolored appearance thanks to a dense but fine covering
of tan pubescence on their lower surfaces, as well as on petioles
and twigs. Blades are widely elliptical in shape - sometimes nearly
orbicular - with prominent, pinnate venation and short drip tips.
Varying widely in size, leaf dimensions range from 13-22 cm in
length and 6-11 cm in width. Old leaves redden before falling
and the tree's green crown, mottled with patches of scarlet, is
an identifying characteristic for this species. Flowers
are imperfect, with male and female blossoms borne on different
trees (Pilon is dioecious). Both types of flowers grow from leaf
axils on large (7 cm), branched panicles. They are tiny (2 mm
in diameter), green, and petal-less, with only a few short stamens
(male) or vestigial staminate appendages (female) to adorn them.
Flowering periods are complex and bi-annual, with male trees blossoming
for much more extended periods than females. The main flowering
season for male trees begins in August and lasts through November,
while female trees are fertile only from late September through
October. Males resume flowering in February and continue through
early April, with females participating in late February. Fruits
are produced rapidly after the females flower. Each panicle supports
tens of small (3 mm - spherical drupes that ripen from green to
a deep red wine color. A single white seed (1.5 mm) is contained
within the juicy pulp. Harvests are also bi-annual and their intensity
varies from season to season. Each begins about six weeks after
flowering, the first lasting from December through January and
the second from mid-May through mid-June.
