Paphiopedilum tonsum

Paphiopedilum tonsum (Rchb.f.) Stein is a distinctive cool-growing, single-flowered Paphiopedilum native to northern and western Sumatra, Indonesia. It grows in humid montane habitats, often in shady pockets of leaf litter and humus over limestone and other rocky substrates, at elevations reported around 1,000–1,800 m.

The plant forms compact fans of deep green leaves mottled with gray-green markings, with attractive purple coloration on the undersides. Each growth produces an erect flower spike bearing a single flower, with blooms reaching approximately 10 cm across. The species is particularly recognizable for its relatively smooth, non-hairy flower, which is reflected in the meaning of the name tonsum.

Care Tips:

• Light: Provide moderate, filtered light or light shade. Avoid strong direct midday sunlight. AOS recommends approximately 1,000–2,000 foot-candles for Paphiopedilums.
• Watering: Keep the growing medium consistently moist but never waterlogged. Allow slight drying between waterings, but avoid prolonged dryness.
• Growing Medium: Use a moisture-retentive but airy Paphiopedilum mix, such as fine bark, perlite, and suitable organic material. A small amount of calcareous material can be appropriate because the species is associated with limestone habitats.
• Humidity: Moderate to high humidity is beneficial, together with good air circulation. Avoid stagnant, constantly wet conditions.
• Temperature: P. tonsum is a cool-growing species. It is best kept cooler than warm-growing mottled-leaf Paphiopedilums, with approximately 15–23°C (59–73°F) suitable and cooler nights beneficial. Its natural habitat is at relatively high elevations.
• Fertilizing: Feed with a diluted balanced orchid fertilizer during active growth. Flush the medium periodically with clean water to prevent fertilizer-salt buildup.
• Airflow: Provide gentle, continuous airflow, especially when humidity is high.
• Potting: Use a relatively small pot with good drainage. Repot approximately every two years or when the growing medium begins to break down.
• Flowering: Keep conditions stable while the single flower develops. Avoid sudden temperature or watering changes during bud development.