Xanthosoma stenospathum Madison

• Genus: Xanthosoma
• Botanical Background: Described by Michael T. Madison, a botanist recognized for his work on aroids and neotropical Araceae, particularly in Central and South America.

• Geographical Range: Endemic to Ecuador
• Environment: Thrives in humid, shaded understory conditions with warm temperatures, consistent moisture, and organically rich, well-draining soils.

Leaves

• Foliage is deeply pinnatifid (lobed), forming a dramatic, divided appearance
• Leaf blades are typically large, leathery, and a deep green.

Inflorescence (Spadix & Spathe)

• Produces a narrow, elongated spathe from which the species name derives (“steno” meaning narrow)
• Spadix is upright and pale, likely pollinated by small insects such as beetles

Growth Habit

• Terrestrial species with a tuberous rootstock
• Form a clumping growth habit in forest-floor environments

Light Requirements

• Bright, indirect light
• Direct sun to prevent leaf scorch

Watering & Humidity

• Requires consistently moist but not waterlogged soil
• High humidity (above 70%) is ideal

Soil & Potting Mix

• Best grown in a rich, loose substrate with good aeration
• Mix of loam, compost, and coarse perlite or bark

Temperature & Fertilizer

• Ideal temperatures range between 20–28°C (68–82°F)
• Balanced liquid fertilizer every 4–6 weeks during active growth helps maintain vigor

Division

• Propagated by dividing the tuber or rhizome
• Ensure each section includes at least one growth point or bud

Seeds

• Propagation is rarely practiced but possible
• Require warm, humid conditions and germinate slowly

Typical Issues

• Mealybugs, spider mites, and scale insects
• Poor drainage may lead to fungal infections like root rot

Treatment Recommendations

• Use neem oil or insecticidal soap for pest control
• Avoid overwatering and provide proper air circulation to reduce disease risk

• Name, stenospathum, refers to its narrow floral spathe, a distinguishing feature among Xanthosoma species

• Sculptural, deeply lobed leaves make it appealing for tropical plant collectors
• Remains very rare in cultivation

Wild Population Status

• Not currently assessed by the IUCN
• Face threats from habitat loss and deforestation

Market Availability

• Extremely rare in horticultural trade
• Found only in scientific collections or among specialized aroid collectors