Andean Lupin
Lupinus mutabilis
The Andean Lupin (Lupinus mutabilis), also known as tarwi, chocho, or pearl lupin, is a species of flowering plant in the legume family Fabaceae, domesticated and cultivated for its protein-rich seeds in the high Andes for thousands of years.
• One of the most important traditional food crops of the Andean highlands of South America
• A nitrogen-fixing legume that plays a vital role in indigenous agricultural systems
• Seeds contain approximately 40–50% protein and 15–25% oil, making them one of the most nutritionally dense plant foods in the Andes
• Despite its remarkable nutritional profile, it remains relatively obscure outside its native region
Taxonomy
• Archaeological evidence suggests domestication began at least 1,500–2,000 years ago, with some researchers arguing for a domestication history stretching back over 5,000 years
• Wild ancestor is believed to be Lupinus piurensis, found in the northern Andes of Peru
• Was a staple food of pre-Columbian Andean civilizations, including the Inca Empire, where it was cultivated alongside quinoa and potatoes
• The Spanish colonial period saw a dramatic decline in tarwi cultivation due to the introduction of European legumes (lentils, chickpeas, broad beans) and colonial policies that suppressed indigenous crops
• Today, it is experiencing a resurgence as interest in ancient Andean superfoods grows globally
Stems & Growth Habit:
• Erect, stout, hollow stems with moderate branching
• Vigorous taproot system capable of fixing atmospheric nitrogen via symbiosis with Rhizobium bacteria
• In favorable conditions, plants can exceed 2 meters in height
Leaves:
• Palmately compound with 5–12 leaflets radiating from a central point
• Leaflets are oblong to lanceolate, typically 5–12 cm long
• Bright green, covered with fine silky hairs
Flowers:
• Arranged in dense racemes (flower spikes) up to 30 cm long
• Individual flowers are papilionaceous (butterfly-shaped), characteristic of the Fabaceae family
• Color ranges from deep blue to violet, sometimes white or pale pink
• Flowers are self-pollinating but can also be cross-pollinated by insects
Seeds & Pods:
• Pods are broad, flattened, and contain 2–6 seeds each
• Seeds are large (~8–15 mm diameter), lens-shaped to nearly round
• Creamy white to pale yellowish in color, resembling flattened beans
• A single plant can produce 50–200+ seeds depending on growing conditions
• Seeds have a characteristically bitter taste due to alkaloid content, which must be removed before consumption
Elevation & Climate:
• Cultivated at altitudes of 2,000 to 4,000+ meters above sea level, one of the highest-elevation grain crops in the world
• Thrives in cool temperatures; optimal growing range is 6–18°C
• Tolerates light frosts and cold nights that would damage most other legume crops
• Adapted to the short growing seasons typical of high-altitude environments
Soil Requirements:
• Prefers well-drained, loamy to sandy soils with moderate fertility
• Tolerates acidic to slightly acidic soils (pH 5.5–6.5)
• As a nitrogen-fixing legume, it improves soil fertility and is traditionally used in crop rotation systems
• Often grown in rotation with potatoes and other Andean tubers
Ecological Benefits:
• Fixes significant amounts of atmospheric nitrogen (estimated 150–200 kg N/ha per growing season) through root nodule symbiosis with Bradyrhizobium bacteria
• Improns soil structure and fertility for subsequent crops
• Deep taproot helps break up compacted soil layers
• Drought-tolerant once established, making it suitable for marginal highland environments
Light:
• Prefers full sun; requires at least 6–8 hours of direct sunlight daily
• At high elevations, intense UV radiation does not damage the plant
Soil:
• Well-drained, moderately fertile loam or sandy loam
• Does not tolerate waterlogged conditions
• Beneficial to inoculate seeds with appropriate Bradyrhizobium strains if the species has not been previously grown in the field
Watering:
• Moderate water requirements; drought-tolerant once established
• Avoid overwatering, which can lead to root rot
• In traditional Andean systems, often grown under rain-fed conditions
Temperature:
• Optimal range: 6–18°C
• Tolerates light frosts (down to approximately -4°C)
• Not suited to tropical lowland heat; performs best in cool highland climates
Propagation:
• Direct seeding after the last frost
• Seeds benefit from scarification or soaking in water for 12–24 hours before planting to improve germination
• Sow at a depth of 2–4 cm, spaced 10–15 cm apart in rows 60–80 cm apart
• Germination typically occurs within 7–14 days
Common Problems:
• Anthracnose (caused by Colletotrichum gloeosporioides) is the most significant disease
• Aphid infestations can affect young plants
• Alkaloid content in seeds requires proper processing (soaking/leaching) before human consumption
Fun Fact
The Andean Lupin is one of the most nutritionally remarkable crops on Earth, yet it remains largely unknown outside the Andes: • With seeds containing up to 50% protein by dry weight, tarwi rivals or exceeds soybeans in protein content — making it one of the most protein-dense plant foods known • The bitter alkaloids (primarily sparteine and lupanine) that protect the plant from herbivores must be removed through a traditional leaching process: Andean communities soak the seeds in running water for 3–5 days, a technique passed down through generations • The Inca Empire valued tarwi so highly that it was cultivated in the sacred terraces of Moray, an archaeological site believed to have served as an agricultural research station where different crops were tested at varying altitudes and microclimates • Modern food scientists are investigating tarwi as a potential global superfood — its high protein and oil content, combined with its ability to grow in cold, marginal highland environments where few other crops thrive, make it a promising candidate for food security in a changing climate • Unlike most legumes, tarwi seeds contain virtually no starch — their energy comes almost entirely from protein and oil, a nutritional profile unique among major food crops
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