Thaumatophyllum × stenolobum variegata

Identity and natural origin of Thaumatophyllum × stenolobum variegata

This variegated cultivated plant is associated with Thaumatophyllum stenolobum.

Kew currently accepts Philodendron stenolobum and lists Thaumatophyllum stenolobum as a synonym. The species is native to Espírito Santo, Brazil.

The origin of the variegated line and the basis for the × used in its cultivated name are still uncertain.

Indoor care for Thaumatophyllum × stenolobum variegata

• Light: Keep it in bright filtered light. Brief gentle sun is suitable when introduced gradually. Pale areas can develop brown marks after a sudden increase in exposure.
• Watering: The surface can dry between waterings while the mix underneath remains lightly moist. Give the whole pot a thorough watering and let it drain well.
• Potting mix: Use bark with coarse pumice or lava in a loose potting mix that holds some moisture and drains freely.
• Temperature and humidity: Keep the plant warm. Moderate humidity and some air movement around the leaves work well.
• Feeding: Feed lightly with a complete houseplant fertiliser while the plant is growing.
• Stability: A heavy pot helps as the plant widens. Add a simple stake if the stem starts to lean.
• Repotting: Choose a larger pot when roots are crowded, the pot dries unusually fast or the plant becomes top-heavy. Keep the stem base at the same depth.
• Propagation: Separate a rooted variegated side shoot, or take a stem cutting with a healthy bud from the same plant. Make sure the cutting also has plenty of green tissue.

Troubleshooting Thaumatophyllum × stenolobum variegata

• Cream areas become dry and brown: Sudden direct sun, a dry potting mix or fertiliser build-up can damage the pale areas. After correcting the cause, watch the next few leaves for new brown areas.
• Several new leaves become much greener: The amount of variegation can change from leaf to leaf. Watch the next few leaves. If a separate side shoot continues to produce only green leaves, remove that shoot at its base.
• Leaves yellow while the potting mix stays wet: Prolonged wetness can stress the roots and lead to rot. Check the roots before watering again. Remove rotten roots with clean scissors, cutting back to firm healthy roots. Discard what you remove and repot in fresh, well-draining mix. The root rot guide covers the remaining recovery steps.
• Small brown bumps, sticky residue or fine pale speckles appear: These signs can point to scale or mites. Check both sides of the leaves and around the thickening base. Keep the plant away from nearby plants while treating it, and follow the product label. The scale guide can help with identification.

Thaumatophyllum × stenolobum variegata is toxic to people and pets

• Keep this plant away from children, cats and dogs.
• Its leaves and stems contain insoluble calcium oxalate crystals, which can irritate the mouth, throat, skin and eyes.
• Chewing may cause burning pain, drooling, swelling, vomiting or difficulty swallowing. Contact a veterinarian or medical professional after exposure, especially if swelling or breathing problems occur.

Why do both Thaumatophyllum stenolobum and Philodendron stenolobum appear?

Thaumatophyllum means ‘wonder leaf’. Stenolobum combines Greek stenós, narrow, with lobós, lobe, meaning ‘narrow-lobed’.

Heinrich Wilhelm Schott established the genus Thaumatophyllum in 1859 in Bonplandia (Hannover), volume 7, page 31.

Eduardo G. Gonçalves first described it as Philodendron stenolobum in 2003 in Aroideana, volume 25, page 3. Cassia Mônica Sakuragui, Luana Calazans, and Simon J. Mayo later placed it in Thaumatophyllum as Thaumatophyllum stenolobum in 2018 in PhytoKeys, volume 98, page 64.

Cassia Mônica Sakuragui, Luana Calazans and Simon Mayo revived Thaumatophyllum for this group in 2018 in PhytoKeys, volume 98. Kew’s World Checklist treats Thaumatophyllum stenolobum as a synonym of Philodendron stenolobum. Both names are still encountered.