Lacmellea panamensis (Woodson) Markgr.
Common Name: CERILLO, ESPINUDO, LAGARTO NEGRO
Occasional evergreen understory or rarely subcanopy tree (15-20
m) found growing under a variety of conditions, but especially
within the semi-darkness of the dense, primary forest. Covered
with broad-based, conical thorns in a way seldom seen among lowland
trees, Lacmellea is a distinctive species, whose thick,
bright green crown is frequently studded with round, yellow fruits
and tubular, white flowers.
Description: A small to medium sized
tree, Lacmellea has a straight and cylindrical (truly columnar)
trunk that may reach 45 cm in diameter. Larger trees may
also sport low, rounded, and short buttresses that barely widen
the base of the bole. Clad in smooth, gray-brown bark, the trunk
is frequently mottled by colonies of flat, blue-gray lichens that
seem to prefer this species. All Lacmellea surfaces exude large
amounts of thick, white latex when broken. Along the upper third
of its length, the monopodial-like trunk gives rise to many, relatively
short, thin branches that leave the bole horizontally but then
droop under their own weight. The crown they produce is at once
narrow and moderately thick. Simple and opposite, Lacmellea leaves
(12 cm by 4.5 cm) are narrowly elliptical in shape. Each glossy,
light green blade bares a contrasting pattern of yellow, pinnately
arranged leaf veins. Flexible and soft as well, the blade is supported
by 1 cm petiole and ends in a 1 cm drip-tip. Most new foliage
is generated from branch tips in December and January. Flowers
(3.5 cm by 1 cm) appear in small, axillary cymes bearing from
one to six blossoms each. Based in a cup-like, five-point, green
calyx, a long, creme-colored tubular corolla dominates each blossom.
This corolla sports two marked swellings: one at its base and
the other two-thirds the way along its length. Just past this
second swelling, the corolla flares into five, yellowish and finger-like
petals. An equal number of stamens are attached to the corolla,
though hidden from view within it. Sporadic flowers may appear
at any time during the year but the most intense and synchronized
blossoming is confined to the months from February to April.
Fruits (4 cm) are rounded
- nearly spherical - drupes, often ending in sharp, distal points.
Initially green and glossy, many of them begin to accumulate in
the Lacmellea crown after flowering, reaching full size quickly
and persisting there for many months before ripening. Slowly and
individually, the fruits turn bright yellow and fall from the
trees. Inside each, a thick layer of soft flesh surrounds two
seeds. Though not all individuals within a given population participate,
many trees possess large numbers of fruits all year long, harvesting
continuously - but slowly - throughout this time.
Similar Species: With its thorned trunk and oppositely arranged leaves, Lacmellea should not be confused with any other tree present on the pacific coast. Fruits, present year round in most individuals, should further aid in the identification of this species.
Natural History: The precise
role of trunk thorns like those possessed by Lacmellea
is open to speculation. Not sharp nor abundant enough to prevent
small mammals (e.g. squirrels, tyras, coatis) from climbing the
bole, they may have once served to deter heavier species. Leaf-eating
giant ground sloths, extinct for the last 10,000 years, were once
present in these woods, and Lacmellea's thorns may have
been intended to keep them from scaling the boles to browse its
foliage. If this indeed was their purpose, the thorns would no
longer confer any advantage to the trees that possess them, and
one might expect to eventually see thornless Lacmellea
trees appearing in the forest. Indeed, a similar process may well
be exemplified by Bombacopsis quinata (Pochote), a dry
forest tree sporting similar thorns to those of Lacmellea.
Certain individuals seen growing in the Nicoya Peninsula's Curu
reserve are indeed spineless.
Croat (1978) suggests that
Lacmellea's deeply-necked flowers are pollinated by long-tongued
bees, butterflies and hawkmoths. He says howler monkeys consume
the fruits while sloths appear to be particularly fond of Lacmellea
foliage.
Uses: Allen (1956) reports that the latexes of several South American species of Lacmellea have been used as chewing gum, as an additive to rubber, and as a milk substitute in coffee
Distribution: Lacmellea is found in primary forests on well drained soils. The species is common in the parks and reserves along Costa Rica's southern Pacific slope (from Carara to Corcovado), though it is found on the country's Caribbean slope as well. It ranges from Belize to Panama.