Mastate (Cow Tree)

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📸 Photo Gallery

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Taxonomy & Classification

Common Names by Region

Etymology

• Brosimum: From Greek "brosimos" meaning "edible," referring to the edible fruits and latex
• utile: Latin for "useful," highlighting the tree's many practical applications
• Mastate/Vaco: From indigenous Central American languages
• Sande: Trade name for the timber in international markets

The Moraceae (fig family) includes many important tropical trees producing edible fruits and latex, including figs, breadfruit, and mulberries.

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Physical Description

Tree Form

Mastate is an impressive emergent canopy tree reaching 30-50 meters in primary rainforest. The trunk is straight and cylindrical, often exceeding 1 meter in diameter, with the first branches typically 15-25 meters above ground. Unlike many emergent species, Mastate usually lacks prominent buttresses, instead having a relatively straight trunk with spreading roots.

The crown is large and spreading, emerging above or within the upper canopy layer. As an evergreen species, the tree maintains its foliage year-round, providing consistent shade and food resources for wildlife.

Bark Characteristics

• Color: Light gray to grayish-brown
• Texture: Smooth to slightly rough
• Features: May have shallow furrows on old trees
• Lenticels: Small, scattered
• Inner Bark: Fibrous, produces abundant white latex when cut
• Latex: Abundant milky-white sap that flows freely when bark is wounded

Leaves

• Type: Simple, alternate
• Shape: Elliptical to oblong
• Size: 15-25 cm long, 5-10 cm wide
• Texture: Leathery, somewhat thick
• Upper Surface: Dark green, shiny, glabrous (smooth)
• Lower Surface: Paler green, may have fine hairs
• Margins: Entire (smooth) to slightly wavy
• Petiole: 1-2 cm long
• Arrangement: Spirally arranged along branches
• Evergreen: Retains leaves year-round

Flowers

• Type: Small, inconspicuous
• Structure: Unisexual (dioecious - separate male and female trees)
• Arrangement: Clustered in globose heads
• Color: Greenish-yellow
• Pollination: Wind and insects
• Timing: March-May

Fruit & Seeds

• Type: Multiple fruit (syncarp) - formed from many flowers
• Shape: Globose to irregular
• Size: 2-4 cm diameter
• Color: Green maturing to yellowish or orange-red
• Texture: Fleshy, slightly sticky
• Seeds: 1-2 per fruit segment
• Dispersal: Primarily by monkeys, birds, and other arboreal mammals
• Edibility: Edible when cooked; eaten boiled or roasted
• Timing: May-September (prolonged fruiting season)

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The Famous "Milk"

Latex Production

Mastate's most famous feature is its abundant white latex, which earned it the name "Cow Tree." When the bark is cut or tapped, copious amounts of thick, white sap flow out resembling cow's milk in appearance.

Characteristics:

• Thick, creamy consistency similar to dairy milk
• Slightly sweet taste
• Nutritious - contains proteins, sugars, and minerals
• Can be consumed fresh or allowed to coagulate
• Safe for direct consumption (unlike many tree latexes)

Traditional Uses of Latex

As Food:

• Drunk fresh as a milk substitute
• Used in coffee like dairy creamer
• Made into a cheese-like product when coagulated
• Used in traditional cooking and beverages

Other Uses:

• Chewing gum base (similar to chicle)
• Candle wax when processed
• Traditional medicine for stomach ailments
• Adhesive for various purposes

Historical Significance: European explorers were amazed by the "vegetable cow" and reported on it extensively. Indigenous peoples have relied on Mastate latex as a protein source for millennia, especially during seasons when other foods are scarce.

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Geographic Distribution

Costa Rica Distribution

Mastate occurs primarily in wet lowland and foothill forests on both Caribbean and Pacific slopes:

• Caribbean Lowlands: Common in Limón Province, Tortuguero, Sarapiquí
• Pacific South: Osa Peninsula, Golfito region, southern Puntarenas
• Central Pacific: Scattered in remaining wet forest patches
• Northern Zone: San Carlos lowlands, Los Chiles region

Elevation Range

• Primary Range: 0-500 m (lowland rainforest)
• Extended Range: Up to 900 m in favorable sites
• Optimal: Lowland to lower premontane wet forest below 600 m

Habitat Preferences

• Forest Type: Primary and mature secondary wet forest
• Position: Emergent to upper canopy layer
• Topography: Well-drained slopes, ridges, and alluvial terraces
• Soil: Tolerates various soil types but prefers deep, moist soils

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Habitat & Ecology

Ecological Role

Keystone Species: Mastate is considered a keystone species due to its prolific fruit production and year-round availability of food resources. The extended fruiting season (May-September) provides critical food when other trees are not fruiting.

Wildlife Food Source: The fleshy fruits are consumed by:

• Primates: Howler monkeys, spider monkeys, capuchins
• Birds: Toucans, parrots, guans, tanagers
• Bats: Fruit bats disperse seeds at night
• Other Mammals: Kinkajous, coatis, peccaries feed on fallen fruits

Canopy Structure: As an emergent tree, Mastate contributes to vertical forest structure, providing nesting and foraging habitat in the upper canopy and emergent layer.

Soil Improvement: Like other Moraceae, Mastate contributes to soil fertility through leaf litter decomposition.

Wildlife Associations

• Seed Dispersers: Primates are primary seed dispersers, carrying fruits long distances
• Nesting Birds: Large crown provides nesting sites for hornbills, raptors, and other canopy birds
• Epiphytes: Branches support diverse orchids, bromeliads, ferns, and mosses
• Insect Pollinators: Various beetles and flies pollinate the small flowers

Special Adaptations

Copious Latex Production: The abundant latex may serve as defense against herbivores and pathogens, while also providing an emergency water and nutrient source for the tree.

Prolonged Fruiting: Extended fruit production (4-5 months) ensures year-round food availability and improves seed dispersal success.

Shade Tolerance: Seedlings can survive in understory shade for years, growing rapidly when gaps form - a strategy allowing establishment in mature forest.

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Uses & Applications

Timber & Wood Products

Wood Properties:

• Color: Pale yellow to light brown heartwood and sapwood (indistinguishable)
• Grain: Straight to shallowly interlocked
• Texture: Medium to coarse, uniform
• Density: Light to medium weight (specific gravity 0.35-0.45)
• Durability: Low to moderate - not durable in ground contact
• Workability: Excellent - easy to saw, plane, nail, glue, and finish

Applications:

• Furniture: Tables, chairs, cabinets, interior furniture
• Plywood: High-quality face and core veneer
• General Construction: Interior framing, moldings, trim
• Molds and Patterns: Model-making, foundry patterns
• Pulpwood: Paper production
• Crates and Boxes: Lightweight packing

Trade Name: Marketed internationally as "Sande," the wood is valued for its workability and light color.

Limitations: Poor resistance to decay and insect attack limits outdoor use. Best for interior applications and protected structures.

Food Uses

Latex ("Milk"):

• Fresh consumption as beverage
• Coffee additive
• Cheese-like product when coagulated
• Traditional ceremonial uses

Fruit:

• Boiled or roasted for consumption
• Not typically eaten raw (somewhat sticky)
• Wildlife food source
• Emergency food in forest

Fiber & Traditional Crafts

Bark Fiber:

• Processed to make cloth (bark cloth)
• Traditional blankets and wraps
• Historically used for sail-making in some regions
• Cordage and rope

Traditional Medicine

• Latex: Stomach ailments, digestive issues
• Bark Decoctions: Various traditional remedies
• Modern Use: Limited scientific research on medicinal properties

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Cultural Significance

Indigenous Knowledge

Mastate holds a special place in indigenous forest cultures as the "Cow Tree" - a source of vegetable milk in the forest. Indigenous peoples have long known where Mastate trees grow and visit them seasonally to collect latex as a protein supplement, especially during lean times between harvests.

The discovery of safe, drinkable tree latex amazed European explorers in the 1700s and 1800s. Accounts describe indigenous people tapping trees early in the morning and collecting the "milk" in gourds to drink fresh or use in cooking.

Traditional Bark Cloth

In some regions, the fibrous inner bark was processed to make cloth. The bark would be carefully stripped, soaked, and beaten to separate fibers, then woven or felted into fabric for clothing, blankets, and ceremonial items. This practice dates back centuries and demonstrates the tree's versatility.

Modern Agroforestry

Today, Mastate is increasingly recognized for agroforestry systems. Its moderate growth rate, valuable timber, wildlife benefits, and edible latex make it attractive for sustainable forestry. Some projects are exploring commercial latex production as a non-timber forest product.

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Conservation Status

IUCN Assessment

Status: Least Concern (LC)
Population Trend: Stable to locally declining
Assessment: Not currently threatened globally

Current Situation

While not globally threatened, Mastate faces localized pressure:

• Selective Logging: Valuable timber leads to harvesting in accessible areas
• Habitat Loss: Deforestation of primary forest reduces populations
• Localized Depletion: Some areas have few remaining large trees

Advantages:

• Occurs in protected areas throughout range
• Regenerates well in secondary forest
• Not listed in CITES
• Used in reforestation projects

Protection Measures

• Protected in Costa Rican national parks and reserves
• Included in sustainable forestry programs
• Used in agroforestry and forest restoration
• Seed banks maintain genetic diversity

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Cultivation & Care

Growing Requirements

Climate: Tropical humid to wet climates. Requires year-round warmth (minimum 18°C), high humidity (70%+), and abundant rainfall (2000-4000mm annually). Brief dry periods tolerated once established, but not suitable for seasonal dry climates.

Site Selection: Best for:

• Tropical reforestation projects
• Agroforestry systems
• Large rural properties
• Forest enrichment planting
• Riparian buffer zones

Not Suitable For:

• Urban or suburban yards (too large)
• Areas with infrastructure (power lines, buildings)
• Truly dry regions
• Frost-prone locations

Soil: Adaptable to various soils:

• Tolerates acidic to slightly acidic (pH 4.5-6.5)
• Requires good drainage
• Performs best in deep, fertile, moist soils
• Can grow in moderately poor soils
• Avoid waterlogged sites

Propagation

Seed Collection:

• Collect ripe fruits (yellowish/orange color)
• Extract seeds from fleshy pulp
• Seeds viable for only 2-4 weeks - plant immediately
• Store in moist conditions if brief storage needed

Germination:

• Sow fresh seeds in well-draining potting mix
• Keep in shade or filtered light
• Maintain consistently moist
• Germination typically 2-6 weeks
• Germination rate 60-80% with fresh seeds

Vegetative Propagation:

• Cuttings can be rooted with moderate success
• Use semi-hardwood cuttings with rooting hormone
• Maintain high humidity during rooting

Nursery Care:

• Grow in partial shade for first 6-12 months
• Gradually acclimate to brighter light before outplanting
• Transplant to larger containers as needed
• Outplant when 40-60 cm tall (12-18 months)

Planting

Timing: Beginning of rainy season for best establishment

Site Preparation:

• Clear competing vegetation in 2-meter radius
• Dig hole 2x root ball size
• Add organic matter only if soil severely degraded
• Minimal fertilization - tree adapted to low-nutrient soils

Spacing:

• Timber production: 10-12 m spacing
• Agroforestry: 15-20 m from other large trees
• Isolation: 20+ m from buildings/infrastructure

Establishment Care:

• Water weekly during dry periods in first year
• Mulch around base (not touching trunk)
• Protect from grazing animals
• Monitor competing vegetation

Maintenance

Years 1-2:

• Clear competing vegetation 2-3 times annually
• Water during extended dry periods
• Protect from browsing damage
• No fertilization needed typically

Years 3-5:

• Reduce weeding to once per year
• Tree becomes self-sufficient
• Monitor health and growth
• Allow natural crown development

Mature Trees:

• No maintenance required in natural or agroforestry settings
• Do not prune - let grow naturally
• Monitor for safety hazards near infrastructure
• Harvest sustainably if grown for timber

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Identification Tips

Key Identification Features

1. Abundant White Latex: Cut bark produces copious milky-white sap - diagnostic
2. Large Dark Green Leaves: Leathery, shiny, elliptical leaves 15-25 cm long
3. Smooth Gray Bark: Relatively smooth bark without deep furrows
4. Globose Fleshy Fruits: Orange-red multiple fruits 2-4 cm diameter
5. Emergent Stature: Tall tree rising above canopy in mature forest

Similar Species

Brosimum alicastrum (Breadnut/Ramón):

• Also produces white latex
• Smaller leaves (8-15 cm)
• Different fruit structure (single-seeded drupes)
• More common in dry to moist forest

Castilla elastica (Rubber Tree):

• Produces white latex
• Latex is more elastic (rubber-like)
• Leaves have more prominent veins
• Different fruit structure

Other Brosimum species:

• Several similar species in genus
• Requires careful examination of flowers, fruits, and leaves
• Distribution and habitat can help distinguish

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Where to See It

Protected Areas in Costa Rica

Caribbean Lowlands:

• La Selva Biological Station: Accessible trails with identified specimens
• Tortuguero National Park: Abundant in primary forest
• Braulio Carrillo National Park: Lower elevations

Southern Pacific:

• Corcovado National Park: Excellent populations
• Piedras Blancas National Park: Mature specimens near Golfito
• Osa Peninsula Private Reserves: Various reserves with mature trees

Northern Zone:

• Maquenque National Park: Lowland wet forest
• Caño Negro area: Riparian forests

Viewing Tips

• Look for large emergent trees with smooth bark
• If accessible, cut small twig to see diagnostic white latex
• During fruiting season (May-Sept), watch for monkeys feeding in crown
• Local guides can point out "milk trees" known to indigenous communities
• Some eco-lodges have marked specimens on nature trails

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References

1. Useful Tropical Plants Database - Brosimum utile
2. The Wood Database - Sande (Brosimum utile)
3. Organization for Tropical Studies - Species Accounts
4. Tropical Restoration Library - Brosimum utile
5. Flora Mesoamericana - Moraceae
6. Plants of the World Online - Kew Science
7. Local observations and indigenous knowledge

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Last updated: January 14, 2026