Trichocentrum jonesianum (Rchb.f.) M.W.Chase & N.H.Williams is an unusual epiphytic orchid native to southern Brazil, Paraguay and Uruguay, where it grows on trees in riverine forests. Formerly classified as Oncidium jonesianum, it is commonly known as a rat-tailed Oncidium because of its long, cylindrical, succulent leaves. This distinctive species produces arching to pendant flower spikes bearing several long-lasting, nodding flowers. The flowers are white to pale yellow, decorated with prominent chestnut-brown to reddish-brown spots, with a contrasting white lip.
Care Tips:
Light: Provide bright light, ideally with some gentle morning sunlight. Avoid excessive, intense midday sun that can scorch the leaves.
Watering: Water thoroughly during active growth, then allow the roots to dry quickly. This species is particularly sensitive to roots remaining wet for extended periods.
Growing Medium: Mount on cork or tree fern with good airflow, or use a very open, fast-drying orchid medium. Mounted plants generally require more frequent watering.
Humidity: Maintain moderate to high humidity with excellent air circulation. Even when the surrounding air is humid, the roots should not remain constantly wet.
Temperature: Adaptable to cool through warm conditions. Aim for approximately 18–30°C (64–86°F), with good ventilation during hot weather.
Airflow: Provide continuous gentle airflow, especially when growing in humid conditions.
Fertilizing: Apply a diluted balanced orchid fertilizer during active growth. Reduce feeding when growth slows.
Seasonal Care: Avoid keeping the plant excessively wet during cooler or less active periods, but do not leave it dehydrated for prolonged periods.
Flowering: Bright light, healthy mature leaves, quick-drying roots and good air movement help promote flowering. Blooming is often reported from late summer into autumn.
