Xanthosoma rupununiense Croat & Delannay

• Genus: Xanthosoma
• Botanical Background: Described by botanists Thomas B. Croat and Bertrand Delannay, the species name “rupununiense” references the Rupununi region in southern Guyana where the plant was first collected and studied.

• Geographical Range: Native to southern Guyana
• Environment: Grows in seasonally moist or riparian zones, often near streams or wet forest edges. Prefers warm, humid climates with rich, well-draining soil and partial shade.

Leaves

• Large, arrow-shaped leaves with smooth margins and a rich green surface
• Venation is pronounced, especially on mature foliage

Inflorescence (Spadix & Spathe)

• Inflorescence features a pale to cream-colored spathe and a stout, fleshy spadix
• Flower structure is consistent with other Xanthosoma species and likely attracts beetle pollinators

Growth Habit

• Terrestrial with a tuberous growth form
• Forms upright clumps from underground storage organs and does not climb or spread via stolons

Light Requirements

• Bright; indirect light
• Tolerates partial shade, especially in warmer regions

Watering & Humidity

• Requires consistently moist soil and benefits from high humidity
• Avoid letting the soil dry out completely, especially during active growth

Soil & Potting Mix

• Use a loose, well-aerated mix rich in organic matter
• Combination of peat, compost, and perlite is suitable
• Container culture should allow for tuber expansion
  

Temperature & Fertilizer

• Thrives between 22–30°C (72–86°F)
• Feed monthly during the growing season with a balanced or nitrogen-rich fertilize

Division

• Most commonly propagated through division of its tubers
• Division should contain at least one viable eye or bud

Seeds

• Propagation is not well documented for this species
• Rarely used in cultivation

Typical Issues

• Mealybugs and spider mites
• Root rot if overwatered
• Proper airflow and avoid stagnant moisture

Treatment Recommendations

• Neem oil and insecticidal soap can manage pests
• Ensure good drainage and let the soil surface dry slightly between waterings to prevent rot

• Name pays homage to the ecologically significant Rupununi region
• Known for high biodiversity and unique plant endemism

• Rare in cultivation
• Appeal to collectors seeking unusual Xanthosoma species or those interested in South American flora

Wild Population Status

• Not formally assessed for conservation status
• Restricted range suggests potential vulnerability to habitat changes or deforestation

Market Availability

• Extremely rare in cultivation
• Not available through commercial nurseries. May be found in specialty plant collections or research institutions