Xanthosoma sinnamaryense Croat & Delannay

• Genus: Xanthosoma
• Botanical Background: Xanthosoma sinnamaryense was described by Thomas B. Croat and Bertrand Delannay. The species name references the Sinnamary region, where it was first collected and studied.

• Geographical Range: Native to French Guiana
• Environment: Thrives in warm, humid, and shaded tropical rainforest environments. Prefers organically rich, well-drained soils and areas with consistent rainfall.

Leaves

• Broad, sagittate (arrowhead-shaped) leaves with smooth, dark green surfaces and prominent venation
• Held by long, erect petioles emerging from a tuberous base

Inflorescence (Spadix & Spathe)

• Inflorescence consists of a pale green to yellow spathe surrounding a thick, cylindrical spadix
• Beetle pollination is likely

Growth Habit

• Terrestrial, tuber-forming plant that grows in upright clumps
• Not epiphytic or climbing and relies on underground tubers for anchorage and nutrient storage

Light Requirements

• Bright, indirect light
• Avoid prolonged direct sun to prevent leaf damage

Watering & Humidity

• Requires consistently moist soil and high humidity
• Water regularly but allow the surface to dry slightly between waterings to prevent tuber rot

Soil & Potting Mix

• Prefers a well-draining, organic-rich medium
• Use a mix of peat, compost, and perlite for potted specimens

Temperature & Fertilizer

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

Division

• Propagation is most successful by dividing the tubers
• Section should include at least one viable eye or shoot

Seeds

• Propagation is uncommon

• Not well documented for this species

Typical Issues

• Spider mites, mealybugs, and root rot from excessive moisture
• Monitor regularly and provide good airflow

Treatment Recommendations

• Use neem oil or insecticidal soap to treat pests
• Ensure proper drainage and avoid overwatering to prevent rot and fungal issues

• Narrowly distributed and represents a part of French Guiana’s unique
• Understudied aroid flora

• Appreciated by collectors for its rarity and large tropical foliage
• Limited distribution makes it a noteworthy addition to specialty collections

Wild Population Status

• Not currently assessed by the IUCN
• Narrow range suggests potential conservation concern if habitat loss or disturbance occurs

Market Availability

• Extremely rare in cultivation
• Typically unavailable in commercial trade and mostly maintained in botanical or research collections