Pengua
Scientific name: Macaranga mappa
IUCN Red List threat level: Least Concern
GPS Location: 17° 42′ 56.53″ N, 64° 49′ 46.83″ W
Observations:
Phenological Markers – Pengua (Macaranga mappa)
Overview
Macaranga mappa, commonly known as the Mappa Tree, is a fast-growing tropical tree native to Southeast Asia and the Pacific Islands. Known for its large, heart-shaped leaves with striking venation, this pioneer species plays a key ecological role in forest regeneration. In addition to its ecological significance, the tree is culturally important, especially in the Pacific Islands, where its leaves have traditionally been used to wrap food or as thatching material.
Scientific Classification
- Family: Euphorbiaceae
- Genus: Macaranga
- Species: M. mappa
- Common Names: Mappa Tree, Ant Tree, Bingabing (Philippines), Daun Gatal (Indonesia)
Physical Description
- Height: Reaches 10–15 meters (33–50 feet) in height under favorable conditions. It has a generally upright habit and a loosely spreading crown.
- Trunk and Bark: Slender trunk, often with smooth, light gray bark.
- Leaves: Exceptionally large, broadly ovate to heart-shaped leaves, often measuring 30–60 cm (12–24 inches) across. Leaves have prominent palmate veins and a slightly rough or hairy surface.
- Flowers: Tiny, yellow-green flowers grow in terminal panicles. Male and female flowers are borne on separate trees (dioecious).
- Fruits: Small, capsule-like fruits are covered with spiny projections and contain 1–3 seeds each.
- Ant Associations: The tree often hosts colonies of ants in its hollow stems or petioles, offering shelter in exchange for protection from herbivores—an example of mutualism.
Habitat and Distribution
Macaranga mappa is native to lowland rainforests and disturbed areas throughout the Philippines, Indonesia, Papua New Guinea, and the Solomon Islands. It is a pioneer species, often one of the first trees to colonize cleared or degraded land, playing an important role in forest succession.
The tree prefers warm, humid climates and well-drained soils. While not native to the Caribbean, it may occasionally be found in tropical botanical gardens or research collections.
Ecological Significance
- Pioneer Species: Rapidly colonizes open ground after disturbance, helping stabilize soil and create shade for more sensitive forest species.
- Ant Mutualism: Provides habitat for ants that, in turn, defend the tree from herbivorous insects.
- Wildlife Value: Fruits and leaves may be browsed by insects and mammals. The flowers are small but can attract pollinators.
- Cultural Uses: In the Pacific Islands, large mappa leaves are traditionally used for wrapping food (especially during steaming), and sometimes as thatching or temporary shelter.
Phenological Markers
| Phenological Phase | Observations |
|---|---|
| Leaf Flush | Young leaves emerge reddish or bronze-colored before maturing to green. New flushes often follow rainfall or after pruning. |
| Full Foliage | Mature leaves are large, bright to dark green, and fully expanded. Can persist year-round in humid, tropical environments. |
| Leaf Drop | Occasional leaf shedding occurs during drought stress or at the end of a flush cycle. Rarely fully deciduous. |
| Flower Budding | Tiny flower buds appear at branch tips, often coinciding with periods of new leaf flush. May occur seasonally or opportunistically. |
| Flowering | Small, pale yellow-green flowers bloom in panicles. Male and female flowers are found on separate trees (dioecious). |
| Fruit Set | Following female flowering, small spiny capsules form and develop over several weeks. Fruiting is often seasonal but can occur year-round in optimal conditions. |
| Seed Dispersal | Mature fruits split open, releasing seeds. Seeds are often dispersed by gravity and possibly by ants or small animals. |
| Ant Activity | Ants commonly inhabit hollow petioles or stems. Activity may increase with new growth or during flowering. |
Growing Conditions
- Light: Prefers full sun to light shade. Grows rapidly in open areas.
- Soil: Tolerates a range of soils but prefers moist, well-drained conditions.
- Water: Moderate to high water needs; sensitive to prolonged drought but capable of surviving short dry spells.
- Climate: Thrives in lowland tropical climates; sensitive to cold and frost.
Propagation
- Seeds: Primary method. Seeds should be sown fresh for best germination rates. Germination typically occurs within 2–4 weeks.
- Cuttings: Possible, but less common. Rooting hormone and high humidity are recommended.
Conservation Status
Macaranga mappa is not considered threatened and is widespread in its native range. As a pioneer species, it plays a restorative role in degraded forest systems and is sometimes planted for reforestation and erosion control.
Notes for Phenology Monitoring
- Observe leaf color changes during early growth and post-rain events.
- Record presence of flowers and fruit on both male and female specimens.
- Document ant activity, particularly in relation to new growth and insect pressure.
- Track flowering and fruiting cycles to determine seasonal vs. opportunistic behavior in your local climate.
Conclusion
Macaranga mappa is an ecologically valuable species, balancing rapid growth, habitat support, and an intriguing mutualism with ants. Its massive leaves and unique reproductive traits make it a standout subject for phenological study, particularly in restoration zones and tropical arboretums. By documenting its seasonal rhythms, we gain insight into how fast-growing tropical pioneers respond to environmental cues—and how they help repair disturbed ecosystems.