Thaumatophyllum tweedieanum

Natural range of Thaumatophyllum tweedieanum

Thaumatophyllum tweedieanum is native to parts of central and southern South America, including Bolivia, Paraguay, Uruguay, north-eastern Argentina and Brazil. It grows in freshwater swamps, marshes, wet grasslands and river deltas, where the ground stays waterlogged and plants may stand in shallow water at times.

The creeping stem and roots stay consistently moist in these open wetlands. The foliage also receives bright light and regular air movement.

Indoor care for Thaumatophyllum tweedieanum

• Light: Bright filtered light suits this species. A little direct morning or late-day sun is also suitable when introduced gradually.
• Watering: Keep the potting mix consistently moist. Water before the pot dries deeply, soaking the mix thoroughly and allowing the excess to drain.
• Potting mix: Use a moisture-holding potting mix that drains freely, with fine bark and pumice or perlite.
• Temperature and humidity: A warm room and normal household humidity are suitable.
• Feeding: A light dose of complete houseplant fertiliser is enough while the plant is putting out leaves.
• Growth and pot shape: A wider, stable pot allows the stem to spread sideways.
• Repotting: Repot when the creeping stem reaches the edge of the pot, roots fill the container or the potting mix becomes compacted. Keep the top of the stem at the same depth.
• Propagation: Divide a rooted section of the creeping stem that has a new shoot, keeping enough roots attached for the new plant to start growing again.

Common problems with Thaumatophyllum tweedieanum

• Leaves droop and the pot feels unusually light: The potting mix has probably dried too far. Water thoroughly and shorten the interval before the next watering.
• Several leaves yellow while roots become brown, soft or sour-smelling: This species prefers steady moisture, and its roots also need an airy, freely draining potting mix. Dense potting mix can hold too little air around the roots and allow rot to develop. 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.
• Water-soaked patches spread quickly or soft tissue smells unpleasant: These symptoms can indicate bacterial soft rot. Isolate the plant and keep the leaves dry. If the affected area is still small, remove all soft tissue with a clean, disinfected tool, cutting back until only firm healthy tissue remains. Discard everything removed. Discard the plant if the rot continues spreading.
• Small brown bumps, fine pale speckles or silvery marks appear on the leaves: These signs can indicate scale, mites or thrips. Check both sides of the leaves and where the leaf stalks meet the stem. Keep the plant away from nearby plants while treating it, and follow the product label. The scale guide can help with identification.

Thaumatophyllum tweedieanum 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.

Thaumatophyllum tweedieanum and Philodendron tweedieanum: why did the name change?

Thaumatophyllum means ‘wonder leaf’. Tweedieanum honours Scottish plant collector John Tweedie.

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

Heinrich Wilhelm Schott first described it as Philodendron tweedieanum in 1859 in Bonplandia (Hannover), volume 7, page 29. Cassia Mônica Sakuragui, Luana Calazans, and Simon J. Mayo later placed it in Thaumatophyllum as Thaumatophyllum tweedieanum 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 tweedieanum as a synonym of Philodendron tweedieanum. Both names are still encountered.