Rotala sp. 'Yao Yai' Care Guide
Rotala sp. 'Yao Yai' is a Thai locality stem plant of the Lythraceae family that turns light red to orange-red under strong light and CO2.
Compiled by Aquairi from published sources · Published · Updated
Overview
Rotala sp. 'Yao Yai' is a locality form of Rotala from Thailand, in the family Lythraceae. In the trade it is treated as equivalent to the rotundifolia 'Colorata' form. It takes on an especially intense light-red to orange-red colour under good light.
Taxonomy
- Family: Lythraceae
- Genus: Rotala
- Scientific name: Rotala sp. 'Yao Yai'
- Trade note: treated as equivalent to R. rotundifolia 'Colorata'
Habitat
The form is associated with a locality in Thailand. Within the genus, round-leaved Rotala such as R. rotundifolia grow as common weeds in rice paddies and wet places across South and Southeast Asia, with the submerged leaf form being narrow and lanceolate.
Tank requirements
- Temperature: 22-28 °C
- pH: 5.5-7.0
- GH: 1-8 °dGH
- Lighting: high
- CO2: required
- Maximum height: about 30 cm
- Placement: midground
Care and growth
Strong lighting and CO2 injection are recommended for optimal colour development and growth. The leaves are narrow and the stems have an overhanging to horizontal growth habit. As with related round-leaved Rotala, balanced macro- and micronutrient supply via the water column supports vigorous growth.
Propagation
Propagation is by cuttings replanted into the substrate. Regular trimming promotes branching and a denser group.
Propagating Rotala sp. 'Yao Yai': Cuttings Guide
Overview
Rotala sp. 'Yao Yai' is a robust, large-form Thai locality cultivar of the Rotala rotundifolia group (family Lythraceae), with broader, slightly serrated leaves that take on rich orange-red tones under high light and CO2. The parent species is a common weed in rice paddies and wet places across India, China, Taiwan, Thailand, Laos and Vietnam, growing both submerged and emersed; the emersed form has rounded leaves, the submerged leaves are narrow and lanceolate, and under strong light leaves can become almost wine red.
Being a rotundifolia-group cultivar, 'Yao Yai' is propagated exactly like Rotala rotundifolia: by cuttings. Its larger, sturdier stems make handling and replanting easy.
Propagation Method (Cuttings)
Propagation is by cuttings. Removing the apical bud encourages lateral buds to develop along the stem at the internodes, so each topped stem branches and grows bushier. Replant the cut top as a new plant; the remaining base produces side shoots below the cut.
Step-by-Step
- Pick a strong stem with well-colored tops, at least 12-15 cm tall.
- Cut the top 5-10 cm with clean, sharp scissors.
- Strip the lowest 2-3 cm of leaves so they do not rot under the substrate.
- Plant the bare base firmly into nutrient-rich substrate, spacing for light penetration.
- Leave the original base; it will push lateral shoots from internodes under the cut.
- Maintain high light and CO2 so the replanted tops root quickly and color up orange-red.
Conditions for Healthy Growth
The parent species is undemanding but requires light to thrive; loss of lower leaves signals insufficient lighting. For 'Yao Yai' aim high: sufficient coloration begins around 80 umols of PAR, with the strongest color at 150-200 umols PAR. Like other rotundifolia forms it reddens under nitrate limitation: high nitrate keeps shoots green/yellow, moderate nitrate gives slightly orange/green shoots, and steep, prolonged nitrate limitation turns leaves dark red. Rotala can grow without CO2 but is much harder to keep healthy that way.
Trimming & Maintenance
Trim roughly every 10 days. Each topping removes the apical bud and triggers new lateral branching, multiplying the plant while keeping the stand dense. Replant the harvested tops to expand the group, and cut away old leggy bases that have lost their lower leaves.
Common Challenges
Bare lower stems and dropped leaves mean too little light. Thin, weakly branching stems indicate low CO2 or nutrients. If tops stay green rather than orange-red, nitrate is likely too high or light too weak. Note that the parent species is often confused with the closely related Rotala indica, which differs in inflorescence structure.