Guaba Machete (Giant Ice Cream Bean)

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📸 Photo Gallery

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Taxonomy and Classification

Common Names

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The Remarkable Pods: A Botanical Record

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Physical Description

Tree Form

General Habit: Large, stately tree with spreading, somewhat dome-shaped crown. Trunk is typically straight and cylindrical in forest settings, becoming more massive and buttressed in open-grown specimens. The overall form is elegant and architecturally impressive, befitting the species epithet "spectabilis."

Size: Typically 20-30 meters tall in natural forest settings. Open-grown trees may be shorter (15-20 m) but develop massive, spreading crowns up to 18 meters wide.

Crown: Broad, spreading, and moderately dense. The crown density increases with age, providing substantial shade—an important characteristic for agroforestry applications.

Bark and Trunk

Bark: Smooth to slightly rough, gray to gray-brown in color. Young branches are greenish, becoming gray with age. Mature bark may develop shallow vertical fissures. The bark is relatively thin and can be damaged by fire or mechanical injury.

Trunk: Substantial—mature trees commonly have trunks 40-80 cm in diameter. In forest settings, trunks are straight and cylindrical with little taper. Open-grown or heavily fruiting trees may develop low buttresses or spreading root flanges for stability.

Branching: Main branches emerge at moderate angles, creating strong crotches. The branching pattern is relatively regular, creating a symmetrical crown shape.

Leaves

Type: Alternate, pinnately compound (feather-like arrangement)

Leaflets: Typically 5-7 pairs of leaflets per leaf—fewer than many Inga species. Each leaflet is 10-18 cm long by 4-8 cm wide—quite large for Inga. Leaflets are elliptic to oblong, with smooth margins and gently pointed tips. Upper surface is dark green and glossy; lower surface is paler and may have fine pubescence along veins.

Rachis: The central leaf stem (rachis) between leaflets has prominent, flat wings—a very characteristic feature of most Inga species. A large gland is present between each pair of leaflets.

Arrangement: Leaves are clustered near branch tips, creating zones of dense green foliage with more open spaces along the interior branches.

Flowers

Appearance: Classic Inga flowers—white to greenish-white, brush-like or pom-pom shaped with numerous long, delicate stamens (75-150 per flower). Individual flowers are 4-6 cm across—larger than most Inga species.

Arrangement: Produced in dense elongated spikes or cylindrical heads, 10-15 cm long, emerging from leaf axils or at branch tips.

Timing: Primary flowering January-April in Costa Rica (dry to early wet season). Flowering may be triggered by the onset of rains after the dry season.

Fragrance: Mildly to moderately sweet-scented, especially noticeable at night. The fragrance attracts nocturnal pollinators.

Pollinators: Primarily pollinated by bees (honeybees and large native bees), hawkmoths, and nectar-feeding bats. The flowers produce copious nectar.

Fruit

Type: Legume pod (typical of Fabaceae), but of truly exceptional dimensions.

Dimensions:

• Length: 60-120+ cm (commonly 80-100 cm)
• Width: 3-5 cm
• Thickness: 2-3 cm
• Weight: 1-2 kg per mature pod

Appearance: Very long, sword-like or machete-like pods, slightly flattened, with prominent longitudinal ridges or slight spiral twisting. Color changes from green when immature to yellowish-green or brownish-yellow at maturity.

Seeds: 15-30+ seeds per pod, each surrounded by abundant white, fluffy, sweet pulp (aril). The seeds are arranged in a single row along the length of the pod.

Maturation: Pods mature April-August (approximately 3-4 months after flowering). Mature pods begin to soften and may develop slight yellowish coloration. They do not dehisce (split open) on the tree; instead, they must be manually opened to access the edible pulp.

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Geographic Distribution and Habitat

Native Range

Costa Rican Distribution

Provinces: Most common on the Caribbean slope; less frequent but present on moist Pacific slopes:

• Limón: Common in lowland and foothill rainforests
• Heredia and Alajuela: Caribbean slope pre-montane wet forests
• Puntarenas: Present in South Pacific rainforest regions (Osa Peninsula, Golfito)
• San José and Cartago: Occasional in moist valleys

Elevation: 50-1500 meters; most abundant 200-1000 m

Habitats:

• Lowland and pre-montane tropical wet forests
• Riverbanks and flood-prone areas
• Forest edges and gaps
• Secondary forests
• Shade tree in cacao and coffee plantations (especially Caribbean slope)
• Rural home gardens and small farms

Habitat Characteristics

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Ecology and Natural History

Ecological Role

Nitrogen Fixation: Like all legumes, Inga spectabilis forms symbiotic relationships with Rhizobium bacteria in root nodules. These bacteria fix atmospheric nitrogen, enriching the soil. As a large tree:

Estimated Nitrogen Input: 80-150 kg N/ha/year—higher than smaller Inga species due to larger biomass and leaf area.

Soil Improvement: The abundant leaf litter (hundreds of kilograms per tree annually) decomposes rapidly, adding organic matter and nutrients to the soil. This makes I. spectabilis particularly valuable in agroforestry.

Wildlife Associations

Seed Dispersers:

• Primates: Howler monkeys, white-faced capuchins, and spider monkeys readily consume the pods—they are among the primary dispersers
• Large mammals: Tapirs, white-lipped peccaries, collared peccaries, and agoutis feed on fallen pods
• Large birds: Toucans, parrots, and other large frugivorous birds may peck at accessible pods

Pollinators:

• Large bees (carpenter bees, bumble bees, native orchid bees)
• Honeybees
• Hawkmoths (Sphingidae) - important night pollinators
• Nectar-feeding bats (primarily Glossophaga spp.)

Foliage Consumers:

• Leaf-cutter ants harvest leaves occasionally
• Various caterpillars (lepidopteran larvae)
• Sloths may feed on tender foliage

Habitat Provider: The large crown provides shelter and nesting sites for numerous bird species. Epiphytes (orchids, bromeliads, ferns) commonly colonize the branches, further increasing habitat diversity.

Forest Dynamics

Successional Role: Early to mid-successional species. I. spectabilis colonizes forest gaps, riverbanks, and disturbed areas, but is not a strict pioneer. It requires some canopy opening or light gap but is more shade-tolerant than true pioneers. Seedlings can survive in moderate shade but require increased light for vigorous growth and pod production.

Canopy Position: Emergent to canopy tree, often extending above the main canopy layer when mature.

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Uses and Applications

Edible Fruit

Pulp Consumption: The white, fluffy pulp (aril) surrounding the seeds is sweet, mildly flavored, and consumed fresh—identical in flavor and texture to other Inga species. What makes I. spectabilis special is the sheer quantity: a single pod may contain 20-30 seed arils, providing far more edible pulp than short-podded species.

Nutritional Content: Primarily carbohydrates (natural sugars) with small amounts of protein, fiber, and vitamins (especially vitamin C). A quick, refreshing snack.

Harvest: Pods are harvested by hand (often requiring ladders or hooked poles for high pods). Harvest when pods turn yellowish and feel slightly soft. Fresh pods are best consumed within 1-2 days; refrigeration extends shelf life to 3-5 days.

Yield: A mature tree can produce 50-100 kg of pods per season—far more edible pulp than smaller-podded Inga species.

Agroforestry Applications

Shade Tree for Coffee and Cacao: I. spectabilis is highly valued as a shade tree, particularly for cacao (chocolate) plantations:

• Shade Provision: The broad crown provides 50-70% shade—ideal for shade-grown cacao
• Nitrogen Enrichment: Leaves and pruned branches add nitrogen to the soil, reducing fertilizer needs
• Quick Growth: Establishes shade canopy relatively quickly (5-8 years to functional shade)
• Edible Pods: Provide supplementary income or food for farm families

Historically used more commonly for cacao than coffee (where lighter shade is preferred), but still utilized in traditional coffee agroforestry.

Alley Cropping and Silvopasture: Planted in rows or as scattered trees in pastures or crop fields:

• Shade for livestock
• Nitrogen input from leaf fall and prunings
• Pods supplement livestock feed (cattle, goats, pigs eat the pulp)

Soil Restoration: Planted on degraded lands to improve soil fertility through nitrogen fixation and organic matter addition. Fast growth and large leaf area accelerate the restoration process.

Timber and Construction

Wood Properties: The wood is light, soft, and not durable—not suitable for quality lumber or outdoor use. However:

• Light Construction: Used locally for temporary structures, interior partitions, fruit crates
• Firewood: Burns readily, though the tree is more valuable alive for nitrogen and fruit
• Pulp: Potentially suitable for paper pulp production, though not currently exploited commercially

Ornamental and Landscape Use

Specimen Tree: The combination of large size, attractive foliage, impressive flowers, and spectacular pods makes I. spectabilis a conversation piece in large parks, botanical gardens, estates, and public spaces. The pods dangling from the crown are unforgettable.

Requirements: Needs ample space (8-12 m clearance) and consistent water. Not suitable for small residential properties.

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Cultural and Historical Significance

Indigenous and Local Use

Indigenous peoples throughout Central and South America have used Inga spectabilis for generations:

• Food Source: The enormous pods provided significant nutrition and were especially valued for travel or long forest excursions.
• Indicator Species: Traditional farmers recognized I. spectabilis as an indicator of fertile, well-watered soils—where it grows naturally, agricultural crops tend to thrive.
• Children's Wonder: The extraordinarily long pods have delighted children for generations—it's impossible to forget your first encounter with a meter-long fruit!

Rural Costa Rica

In rural Costa Rican communities, Guaba Machete is recognized and admired:

• Marvel Tree: Even people who don't eat the fruit stop to marvel at the huge pods—it's a botanical curiosity
• Farm Tree: Valued in traditional agroforestry for nitrogen fixation and shade
• Shared Pride: Families with a mature Guaba Machete on their property often show it off to visitors—it's a point of pride

While not deeply embedded in folklore like some species, Guaba Machete earns respect and wonder wherever it grows.

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Conservation Status

IUCN Red List: Least Concern (LC)

Population Trend: Stable

Threats: Not significantly threatened. Like most Inga species, I. spectabilis is adaptable and commonly cultivated. However, habitat loss (deforestation) reduces wild populations. As a species of wet forests, it's more habitat-specific than I. edulis and less commonly planted outside its native range.

Protection: Not requiring special conservation action, but maintaining wild populations in protected forests preserves genetic diversity for future use.

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Growing Guaba Machete

Ideal Growing Conditions

Climate: Tropical lowlands to mid-elevations with high rainfall. Prefers:

• Warm year-round temperatures (22-28°C / 72-82°F)
• High humidity
• Consistent, abundant rainfall (2500+ mm annually) or supplemental irrigation
• Protection from frost

Soil: Performs best in deep, fertile, well-drained soils:

• Deep alluvial soils along rivers—ideal
• Clay loams with good organic matter
• pH range 5.5-7.0
• Can tolerate poorer soils (nitrogen-fixing) but pod size and quantity may be reduced

Light: Requires full sun for vigorous growth and optimal fruiting. Seedlings tolerate light shade but grow faster in bright light.

Propagation

From Seed (Standard method):

1. Seed Collection: Collect mature pods (yellowish, slightly soft). Extract seeds from pulp. Seeds must be planted fresh—Inga seeds lose viability within days to 1-2 weeks.
2. Planting: Plant fresh seeds 1-2 cm deep in moist soil or potting mix. Germination occurs in 1-3 weeks.
3. Seedling Care: Keep soil consistently moist. Provide light shade for first 2-3 weeks, then full sun. Seedlings grow rapidly.
4. Transplanting: Transplant when seedlings reach 40-60 cm tall (4-8 months). Use care to preserve root system.

From Grafting:

• I. spectabilis can be grafted onto I. edulis rootstock for earlier fruiting and dwarfing (smaller tree size)
• Grafted trees may fruit in 2-3 years vs 4-5 years from seed
• Grafting also allows propagation of superior selections (extra-long pods, high yield)

Planting

Timing: Plant at the start of the rainy season (May in Costa Rica) to minimize irrigation needs.

Spacing:

• Agroforestry plantations: 8-12 m spacing between trees
• Landscape/ornamental: 8-10 m from buildings and other large trees
• Living shade for cacao: 12-15 m spacing (approx. 70-100 trees/ha)

Planting Steps:

1. Dig hole 60 cm deep × 60 cm wide
2. Mix excavated soil with compost or aged manure
3. Place seedling at same depth it was growing in nursery
4. Backfill and firm soil gently
5. Water deeply (20-30 liters)
6. Mulch around base with organic material (leaves, wood chips)
7. Stake if in windy area

Care and Maintenance

Watering: Critical during establishment (first 1-2 years). Water weekly during dry periods—each tree needs 30-50 liters per week when young. Mature trees are more drought-tolerant but fruit better with consistent moisture.

Fertilization: Generally not required due to nitrogen-fixing ability. However, on very poor soils or for maximum pod production:

• Apply compost or aged manure annually (10-20 kg per tree)
• Balanced organic fertilizer (low nitrogen, medium phosphorus and potassium) can improve flowering and pod set

Pruning: Minimal pruning required. Remove dead or diseased branches. In agroforestry settings:

• Prune to raise crown and allow light to understory crops
• Remove low branches for easy access beneath tree
• Prunings can be used as nitrogen-rich mulch or green manure

Mulching: Maintain mulch ring around tree base to conserve moisture, suppress weeds, and add organic matter.

Fruiting and Harvest

Time to First Fruit:

• Seed-grown: 4-5 years; sometimes 3 years in ideal conditions
• Grafted: 2-3 years

Fruiting Season: April-August in Costa Rica (peak May-July)

Harvest Timing: Pods ready when they turn yellowish-green and feel slightly soft. Fully green pods are immature; fully brown pods are overripe. Harvest at the yellow-green stage for best flavor.

Harvest Method:

• Low pods: Hand-pick or use short hooked pole
• High pods: Long hooked pole or "fruit picker" tool
• Pods do not fall naturally when ripe; must be harvested

Yield: Variable. A mature tree in good conditions can produce 50-150 pods per season (50-100 kg total). Pod size and number depend on tree age, water availability, and soil fertility.

Common Problems

Space Requirements: Too large for small properties. Ensure adequate space before planting.

Pod Drop Hazards: While not dangerous, falling 1-2 kg pods can be startling. Avoid planting directly over seating areas, walkways, or parking.

Pod Borers: Caterpillars (moth larvae) occasionally bore into developing pods, causing premature drop or reduced pulp quality. Generally not serious enough to warrant treatment.

Branch Breakage: Branches heavily laden with pods may break in storms. Proper tree structure and pruning when young helps prevent this.

Scale Insects: Occasionally affected; rarely requires treatment. Prune affected branches or apply horticultural oil if severe.

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Where to See Guaba Machete in Costa Rica

National Parks and Protected Areas

• La Selva Biological Station (Sarapiquí, Heredia): Common in secondary forests and along trails; excellent place to observe pods
• Braulio Carrillo National Park (Caribbean slope): Found in lower to mid-elevation zones
• Tortuguero National Park (Limón): Present in riverside and forest edge habitats
• Corcovado National Park (Osa Peninsula, Puntarenas): Present in wet forest areas (less common than Caribbean slope)

Research Stations and Botanical Gardens

• CATIE (Centro Agronómico Tropical de Investigación y Enseñanza) (Turrialba): Planted as shade tree in various agroforestry trials
• Finca La Isla Botanical Garden (Puerto Viejo de Talamanca, Limón): Likely present (inquire locally)

Rural Areas

The best way to see Guaba Machete is to visit cacao-growing regions of the Caribbean lowlands:

• Small cacao farms around Guápiles, Siquirres, Limón, and Talamanca often have these trees as shade
• Ask local farmers for "guaba machete" or "guaba de metro"—they'll know it immediately

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Comparison with Related Inga Species

Key Differences in Common Costa Rican Inga Species

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References and Further Reading

1. Pennington, T. D. (1997). The Genus Inga: Botany. Royal Botanic Gardens, Kew. [The authoritative monograph on all Inga species, including detailed I. spectabilis description]

2. León, J. (2000). Botánica de los cultivos tropicales. San José, Costa Rica: IICA. [Central American agricultural botany reference]

3. Somarriba, E. & Beer, J. (2011). "Productivity of Inga edulis and Erythrina spp. in Agroforestry Systems." Agroforestry Systems 81(1): 67-78. [Research on Inga in agroforestry; principles applicable to I. spectabilis]

4. Beer, J. et al. (1998). "Shade Management in Coffee and Cacao Plantations." Agroforestry Systems 38(1-3): 139-164. [Classic reference on Inga as shade tree]

5. Cordero, J. & Boshier, D. (Eds.) (2003). Árboles de Centroamérica: Un manual para extensionistas. Turrialba, Costa Rica: CATIE. [Practical silvicultural guide to Central American trees including I. spectabilis]

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Advanced Care Guidance

Site Design and Planting

• Plant with 8-10 m spacing due to large canopy potential and long pod-bearing branches.
• Use humid, fertile soils with strong drainage; avoid compacted sites that limit root expansion.
• Integrate into mixed agroforestry blocks where periodic pruning is feasible.

Watering Program

• Establishment (0-10 months): Water deeply 1-2 times weekly in dry periods.
• Juvenile trees (10-36 months): Irrigate every 7-10 days during dry season.
• Mature trees: Supplemental watering before flowering and pod fill improves yield consistency.

Fertilization Schedule

• Favor low-to-moderate nitrogen with strong potassium and phosphorus support.
• Apply one dose at rainy-season start and one pre-flowering support application.
• Incorporate composted organic matter yearly to sustain biological fertility.

Pruning and Structure

• Build a wide, accessible scaffold for safer pod harvest and reduced branch breakage.
• Prune after harvest cycles to manage vigor and maintain light penetration.
• Remove vertical water shoots that compete with productive lateral branches.

Pest and Disease Management

• Monitor pod borers, mealybugs, and fungal pod lesions in prolonged humid conditions.
• Keep orchard floor clean of fallen pods and prune diseased branch tips promptly.
• Combine sanitation with biological controls and habitat for beneficial insects.

Companion Planting

• Recommended companions: Cacao, coffee in partial-shade systems, Musa spp. in controlled density, and native flowering strips.
• Agroforestry role: Productive nitrogen-fixing canopy species with high litter contribution.
• Avoid nearby: Small high-light crops that cannot tolerate periodic shade shifts.

Seasonal Care Calendar (Costa Rican Conditions)

• Dry season (Dec-Apr): Irrigation support, mulch renewal, and branch safety checks.
• Early rains (May-Jul): Main fertilization, canopy training, and replanting.
• Peak rains (Aug-Oct): Disease monitoring and selective thinning.
• Transition (Nov): Harvest planning and structural pruning adjustments.

Growth Timeline and Harvest Notes

• Strong vegetative development in first 2 years under good moisture management.
• Consistent pod production generally improves from years 3-5 onward.
• Harvest mature pods with clean cuts to avoid tearing branches and opening disease entry points.

External Resources

• 🌍 IUCN Red List - Inga spectabilis↗ - Conservation status (not individually assessed; genus-level)
• 🦋 iNaturalist - Inga spectabilis↗ - Photos and observations worldwide
• 🌿 GBIF - Inga spectabilis↗ - Global occurrence records
• 📚 Tropicos - Inga spectabilis↗ - Botanical nomenclature and synonyms
• 🌱 World Agroforestry (ICRAF) - Inga species database↗ - Agroforestry uses

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