Pouteria foveolata T. D. Penn.
Sapotaceae
NISPERO CHICKLE
Common evergreen subcanopy or occasionally canopy tree (15-22 m) found widely distributed throughout the primary forest. This species produces annual crops of large, milky (edible) fruits that constitute an important food source for many arboreal mammals. Unfortunately, Nispero’s rather ordinary leaves and unremarkable stature make it a difficult tree to identify.
Description: Nispero trees are of moderately large size, with trunk diameters reaching about 70 cm. They are usually positioned with their crowns just beneath the average level of the forest canopy. Nispero boles are cylindrical and straight, with large individuals sometimes sporting abrupt, thin, and somewhat wavy buttresses (smaller specimens usually lack these structures entirely). Textured by shallow, vertical cracking, the bark is mostly smooth and brown in color. Small quantities of exfoliation occur, and large (10 cm), thick plates of bark are shed. The areas of underlying cork exposed by this process typically possess a rich red or rust color. Though few in number, the presence of such highly-contrasting bark scars – a hallmark of Nispero trees – is perhaps the easiest way to identify them in the field. All tree parts, when broken, exude thick, white latex sap. Branches are abundant though they are restricted to the upper third of the bole and, combined with a thick leaf cover, they produce a rounded and very dense crown.
Leaves (13 cm by 3.5 cm) are alternate, simple, smooth and entire. Elliptically shaped and narrow, the glossy green blades taper to well-developed drip tips. Petioles (1 cm) are typically chocolate brown or black in color – significantly darker than the brown twigs to which they are attached – and they are markedly curved. Leaves are arranged in two tiers along either side of the twig, and the curved petioles serve to hold them in a single horizontal plane. New foliage, usually lighter green or sometimes pale orange in color, is produced around December and replaces up to 20% of the pre-existing leaf cover.
Mildly fragrant, flowers (5 mm) emerge from leaf axils in sessile clusters. Each consists of a yellowish calyx made up of five, scale-like sepals; a pale green corolla tube that is divided distally into five short lobes; five stamens inside of, and attached to, the corolla; and a short, fat, central pistil. Before the flower opens, the pistil may be observed protruding from the spherical, scaly bud, ready to receive pollen from another flower’s mature anthers in an effort to avoid self-pollination. Nispero trees flower annually, however the timing of this event varies from season to season. Synchronization among fertile trees is also quite poor. Generally speaking, flowering in this species appears to be a haphazard process that occurs for one or two, two-week periods, sometime between November and February.
Fruits develop slowly into large (4-5 cm), sessile, ovoid berries. Golden and velvety, the thick and woody outer crust conceals a thin, edible layer of milky tissue that – although gooey – has a surprisingly sweet and fresh flavor. A single, large (3 cm), glossy-brown seed lies at the heart of the berry. Typical of the Sapotaceae, the seed’s hard testa is marked by a dull, longitudinal scar. Fruits reach full size and appear ripe by June (some six months after flowering), but tend to persist in the trees for some time after that, finally disappearing only when collected by some arboreal mammal. These extended harvests last from late May through November, with ripe, golden fruits evident in the trees during all of this time. Harvests vary significantly in size from year to year.
Similar Species: Pouteria foveolata has unremarkable foliage, making sterile samples of this species difficult to identify. The list of trees that can be confused with Nispero, based on this feature, is endless, so it is better to focus on some of its more unique traits. Perhaps the best markers in this regard are the occasional, reddish scars (see photo, above) that mottle the trunk in places where plates of older bark have recently exfoliated. This definitive feature is positively identifying for this P. foveolata within its range. In addition, fruits are present on Nispero trees from April through at least November (and sometimes through the following March). Their large size, sessile (branch hugging) nature, and golden color aid greatly in the identification of these trees during the months that they are present.
Natural History: Nispero flowers are pollinated by insects. As has been noted for other species (e.g. Iguano), plants often exhibit devices or behaviors designed to avoid self-pollination. In P. foveolata, this is accomplished through the early maturation of the pistil and its protrusion from a tiny aperture in the otherwise tightly sealed flower bud. By the time this blossom has opened and has begun to attract pollinators, the pre-exposed stigma should already have been fertilized. Nispero fruits are eaten by arboreal mammals like White-faced Monkeys. The dogged persistence of these fruits in the trees, however, gives one the impression that either they are not highly prized by the animal community, or their natural dispersers are no longer present – at least in Manuel Antonio National Park (MANP). Indeed, Manuel Antonio is a tiny island of vegetation – a mere remnant of the lush tropical forest that used to blanket these Pacific lowlands – and it has a similarly fragmented complement of the faunal species that were once native to the area. Perhaps in its natural habitat, in an intact faunal ecosystem, P. foveolata fruits were harvested immediately upon ripening in June and July.
Once dislodged from the trees, ground dwelling Agoutis readily consume Nispero fruits. In addition, some as yet unidentified animal chews through the fruit to get at the seed, which is then eaten instead. Often, whole fruits are found open and discarded on the forest floor, lacking seeds entirely or surrounded by empty, fragmented testa.
Uses: Beneath its tough, woody skin, a Nispero fruit has a layer of milky pulp. Sweet and good tasting, this edible tissue has a gooey consistency.
Distribution: In MANP, P. foveolata trees are common components of primary forests like those in Puerto Escondido, Punta Catedral, and the hills behind Playa Blanca. The species is also known from Corcovado National Park (where it is especially abundant around the La Leona post) and in Punta Leona. It ranges from Nicaragua to Costa Rica.
Images: Tree Leaf Leaf2 Flower Flower2 Fruit&Seed Fruit&Leaf
Trees of Costa Rica's Pacific Slope 