Tawaia sabahensis (S.Y.Wong, S.L.Low & P.C.Boyce) S.Y.Wong & P.C.Boyce

• Genus: Tawaia
• Botanical Background: First described in Webbia (2018) by Wong, Low & Boyce following its original placement in Aridarum (2014). Recent molecular and morphological revisions prompted recognition as a separate genus.

• Geographical Range: Confined to Sabah (Borneo), known only from a few riverine localities on ultramafic (serpentine) substrates.
• Environment: Obligate rheophyte growing on exposed river boulders and waterfall faces under moist lowland tropical forest. Elevational range 135–300 m; requires high humidity (>80%), fast currents, and periodic inundation.

Leaves

• Oblong‑elliptic (4–6 × 1.5–2 cm), glossy dark green above, pale below
• Petiole 3–4 cm
• Pinnate venation with ca. nine lateral veins per side

Inflorescence (Spadix & Spathe)

• Spadix ~3 cm long
• Pistillate zone conoid with globose pistils and cream rhomboidal staminodes
• Spathe nodding, white at anthesis, turning brown and abscising thereafter
• Minimal opening at pistillate phase

Growth Habit

• Terrestrial, rhizomatous herb forming small mats on rocks
• No true tubers
• Specialized attachment roots resist strong currents

Light Requirements

• Bright, indirect light
• Avoid direct sun to mimic shaded stream banks

Watering & Humidity

• Maintain consistently moist substrate
• High humidity (>80%) required
• Avoid standing water to prevent rot

Soil & Potting Mix

• Coarse, rocky mix (river stones + minimal organic matter) for excellent drainage and aeration

Temperature & Fertilizer

• Ideal 20–28 °C

• Fertilize sparingly (quarter‑strength balanced feed) during active growth

Division

• Separate rhizome segments bearing roots and leaves

Seeds

• Rarely used
• Low viability
• Germination likely requires periodic water level fluctuations mimicking natural floods

Typical Issues

• Vulnerable to root rot under poor drainage

• Occasional mealybugs or spider mites

Treatment Recommendations

• Improve aeration
• Treat pests with neem oil or insecticidal soap
• Maintain high humidity without waterlogging

• Unique as the only member of Tawaia
• Exhibits specialized rheophytic adaptations (e.g., narrow leaves, robust anchoring roots) that allow survival in turbulent streams

• Highly prized by specialist collectors for rarity and ecological uniqueness
• Virtually absent from mainstream horticulture

Wild Population Status

• Predicted extinction risk “Threatened” due to extremely restricted range and habitat specificity
• Known only from a few small populations on ultramafic rocks

Market Availability

• Extremely rare

• Only held in a handful of specialist aroid collections

• Not commercially available