Apoballis acuminatissima 'Lavallaei' ('Purple Sword')

Apoballis acuminatissima ‘Lavallaei’ (‘Purple Sword’)

This plant forms a tight clump of long, pointed leaves that rise from a short base. The upper surface is grey-green with darker markings, while the underside shows a clear purple to burgundy tone that also carries through the petioles. Because the leaves angle and overlap, the purple undersides are often partly visible as the plant grows.

Growth comes from a rhizome at the base. New shoots emerge close together and gradually widen the clump. The rhizome should stay lightly moist, but the mix still needs enough air to prevent rot.

It is native to Sumatra, where it grows in wet tropical habitats, and belongs to the Araceae family. In cultivation, it stays compact. Drooping or yellowing often follows drying out, cold conditions or wet soil.

‘Lavallaei’ and ‘Purple Sword’ are names used for this form of Apoballis acuminatissima.

As an aroid, it may produce a spathe and spadix, though the leaves are the main feature indoors.

Rhizome care

• Light: Bright indirect light works best. Gentle morning sun is fine, but strong direct sun can scorch the leaves.
• Watering: Keep the mix lightly moist. Water once the surface begins to dry, then allow excess water to drain away.
• Substrate: Use an open aroid mix with fine bark, coco chips or coco coir, plus perlite or pumice.
• Drainage: Essential. The rhizome should not sit in stagnant water.
• Temperature: Warm conditions around 18–27 °C support steady growth.
• Humidity: Higher humidity helps leaves unfurl without damage.
• Feeding: Use a weak balanced feed while the plant is actively producing leaves; flush occasionally if salts build up.
• Repotting: Repot when the plant fills the pot or the mix breaks down. Keep the rhizome near the surface.
• Propagation: Divide once separate shoots have formed their own roots.

Drooping, yellowing and base softness

• Drooping leaves often mean the root ball is too dry, or too wet with too little air around the roots.
• Yellowing lower leaves are normal occasionally, but frequent loss suggests low light or poor root conditions.
• Brown tips can follow dry air, inconsistent watering or mineral build-up.
• Softness at the base points to rot risk from dense, wet soil.
• New leaves may tear or crisp if moisture or humidity drops while they are opening.
• Spider mites, thrips and mealybugs can gather along midribs and leaf bases.

Remove older leaves cleanly at the base once they decline. Avoid frequent disturbance of the rhizome once the plant is established.

As with other aroids, plant tissue can irritate if ingested. Keep it away from pets and children, and wear gloves if you have sensitive skin.

The name acuminatissima refers to the sharply pointed leaf tips.