Zuelania guidonia (Sw.) Britt. & Millsp.
Flacourtiaceae PATA YANQUI, PLOMILLO
Tree: Occasional deciduous subcanopy – or rarely canopy – tree (20-30 m) exhibiting a monopodial trunk, horizontal branching and a thin crown. It is an especially important component of the forest vegetation found along Manuel Antonio’s sandy coastline. Zuelania‘s common names, loosely translated as “Yank’s Leg” and “Lead Slug”, derive from the pale and warty appearance of the tree’s trunk (!) and the dense, round, and heavy fruits that fall great distances to the ground, respectively.
Description: Zuelania’s buttressless trunk (55 cm) is perfectly cylindrical, very straight, and slowly tapering, with branches restricted to the very top of the tree. There, relatively few, but quite long and flexible, limbs are borne at right angles to the main tree trunk and form a thin, pyramidal crown. The bark is finely textured, light silvery-gray in color, and it is densely covered by elevated, wart-like lenticels. Zuelania leaves (10-15 cm by 3.5 cm) are simple, alternate and have slightly crenulate margins. The thick, leathery, and elliptical to slightly oblanceolate blades are smooth, however veins and petioles (1 cm) are covered by a rust-colored pubescence. Foliage is completely shed in January and early February and, after a short leafless period, begin to re-grow in April from the terminal or subterminal ends of the branches. Trees continue this growth at a slow pace throughout the rainy season. Plomillo flowers (1 cm) appear from late February through April in spherical, head-like clusters at the ends of the leafless branches. Supported at the ends of long pedestals (2 cm), they are green with 5 sepals, no petals, and a ring of numerous short stamens surrounding a central, globular pistil and ovary. The fruit is a large (to 15 cm) globular, dark green berry. Fleshy, soft, and resinous (even zucchini-like), the outer layer of the fruit is responsible for most of its great mass. Upon ripening, this outer husk splits distally into three sections, exposing hundreds of small white seeds cloaked in bright-orange arils. Eventually, these dense bodies come crashing – sloppily – to the ground. Harvests last from April through June, with large crops produced by all individuals on an annual basis.
Similar Species: Though relatively unique, several other Manuel Antonio tree species share Plomillo’s monopodial trunk and horizontally-branched, pyramidal crown. Included among these are Virola koschyni, Virola sebifera, Xylopia sericophylla, Xylopia frutescens, and Aspidosperma spruceanum. Nevertheless, Plomillo can be readily distinguished from them thanks to the heavy covering of wart-like lenticels that populate its bole.
Natural History: Plomillo’s fertility cycle follows a pattern similar to that of a large group of trees adapted to a region with a short but pronounced dry season. Leaves are shed at the outset of the dry period and the tree remains essentially leafless until shortly before the rains resume in April or May: aiding in the conservation of water that would otherwise be lost in large quantities through leaf stoma. When the tree is completely leafless and the dry season is in full swing, flowering commences. This timing is advantageous because delicate flower structures are not adversely impacted by heavy rains, damaging fungal and parasitic diseases are less rampant, and many insect pollinators are more active. Also, flowers are more visible and accessible without the obscuring leaf cover present during most other months of the year. Fruit matures at the end of the dry season, ensuring seed dispersal and germination at the start of the favorable, wet season, and giving the seedlings a chance to establish themselves before the onset of the next dry cycle.
Seeds of Plomillo fruits are dispersed mainly by small birds (e.g. Red-legged Honeycreepers). They fly up and under the vertically hanging, open fruits, pluck the ariled seeds, and deposit them elsewhere – after having digesting the nutritious arils.
Distribution: In Manuel Antonio National Park (MANP), Pata Yanqui is found most frequently amid the forest inhabiting the extreme coastal region, and particularly along the sandy strip of soil behind Playa Espadilla Sur. In Costa Rica, this tree has also been observed in Santa Rosa. It ranges from southern Mexico to northern Venezuela and the Antilles.
Trees of Costa Rica's Pacific Slope 