Apoballis okadae (M.Hotta) S.Y.Wong & P.C.Boyce

• Genus: Apoballis 
• Botanical Background: Originally described in 1987 by Mitsuru Hotta and H. Okada as Schismatoglottis okadae, this species was transferred to the reinstated genus Apoballis by Sin Yeng Wong and Peter C. Boyce in 2010 (Botanical Studies, Taipei 51) to reflect its distinct phylogenetic placement within the Schismatoglottideae.

• Geographical Range: Endemic to Sumatra, occurring in scattered populations in Aceh, North Sumatra and West Sumatra
• Environment: Rheophytic on rocks or in sand and gravel by streams at 50–400 m altitude. Plants often form extensive colonies in well‑lit conditions on limestone or sandstone substrates

Leaves

• Several along creeping stems
• Petiole 5–40 cm long with a basal sheath that later degrades
• Midrib and primary veins tough and prominent on the underside

Inflorescence (Spadix & Spathe)

• Solitary; peduncle about half as long as the petiole at anthesis, then elongating
• Spathe green, total length 5–8 cm; lower spathe narrowly ovoid (2–3 cm), limb oblong‑lanceolate (3–5.5 cm), persistent then deciduous
• Spadix 3–3.5 cm; female zone subcylindric (1–1.5 cm), pistils oblong‑subglobose (~0.5 mm), sparse staminodes at interstice (5–8 mm)

Growth Habit

• Perennial, rhizomatous geophyte
• Stem creeping to decumbent, internodes 1–4 cm long and 1–3 cm thick.

Light Requirements

• Bright, indirect light; mimics streamside dappled conditions

Watering & Humidity

• Keep substrate constantly moist
• Humidity above 70% preferred

Soil & Potting Mix

• Mix coarse sand or gravel with rich organic matter for free drainage

Temperature & Fertilizer

• Maintain 20–28 °C
• Apply balanced liquid fertilizer every 4–6 weeks during active growth

Division and Cuttings

• Separate creeping stems with attached leaves and rhizome sections; plant in moist sandy mix

Seeds

• Sow fresh seeds on damp, sandy substrate; germinate in warm (24–28 °C), humid conditions

Typical Issues

• Mealybugs and aphids
• Watch for root rot if overwatered

Treatment Recommendations

• Improve drainage to prevent rot
• Treat pests with insecticidal soap or neem oil

• Leaf size and robustness vary by microhabitat—smaller on boulders, larger in gravel beds

• Rare rheophytic habit and attractive foliage make it prized in specialized terrariums and paludariums

Wild Population Status

• Predicted as threatened due to habitat disturbance and river alterations

Market Availability

• Rarely encountered outside specialist collections; occasionally offered by boutique aroid growers