🇵🇬 Habitat and Ecology
​Dendrobium auricolor is a captivating epiphytic orchid endemic to the island of New Guinea (encompassing both Papua New Guinea and Indonesian Papua). It inhabits lowland to montane rainforests across a remarkably broad elevational range, from 250 to 2,300 metres. This adaptability allows it to thrive in both hot, humid lowlands and cooler, misty mountain environments, where it grows on the trunks and branches of trees in the wet tropical biome.
​🌸 Description and Distinguishing Features
​This species belongs to the section Diplocaulobium (often treated as a separate genus, Diplocaulobium), known for its distinctive pseudobulb shape and fleeting flowers.
​Pseudobulbs & Foliage: The plant features a unique "flask-like" growth habit. The pseudobulbs are crowded and fusiform (spindle-shaped) at the base, quickly narrowing into a long, slender, neck-like upper portion. These can reach 40-50 cm in length. Each pseudobulb is topped by a single, rigid, narrowly lanceolate leaf.
​Flowers: The flowers are produced singly or in small fascicles from the apex of the pseudobulb (at the base of the leaf). Like many in its section, the blooms are ephemeral, often lasting only one day (sometimes just a few hours), typically opening in the morning and collapsing by evening.
​Aesthetics: The specific epithet auricolor (meaning "gold-coloured") refers to the flower's hue. The blooms are typically star-shaped and widely opening, measuring about 3.7 cm wide. The sepals and petals are usually orange-yellow to pale golden-yellow, sometimes described as having a reddish tint or spots on the lip. The lip (labellum) features wavy keels and is elastically attached to the column foot.
​Differentiation:
​Versus Dendrobium (Diplocaulobium) regale: D. regale typically has pink to magenta flowers, whereas D. auricolor is distinct for its yellow/orange-gold colouration.
​Versus Dendrobium centrale: D. centrale has white or rose-coloured flowers and narrower petals compared to the broader segments of D. auricolor.
​💧 Cultivation and Care
​Dendrobium auricolor is a warm-to-cool growing orchid (depending on the specific clone's origin, but intermediate is a safe baseline) that requires high humidity.
​Light: Requires bright, filtered light. It thrives in positions with good air movement and dappled sunlight, similar to Cattleya conditions.
​Substrate: Due to its creeping rhizome and need for drainage, it is best grown mounted on cork bark or tree fern slabs. If potted, use a small pot with a very open, fast-draining mix of medium bark and charcoal to prevent root rot.
​Watering: Water regularly and abundantly during the active growing season. Ensure the roots dry slightly between waterings but never remain fully dry for long periods. Reduce watering slightly in winter, but do not provide a harsh dry rest as the plant has no massive storage organs.
​Temperature:
​Optimal Daytime Temperature: 22-28 C (72-82 F).
​Optimal Nighttime Temperature: 15-20 C (59-68 F).
​Humidity: High humidity (60-80%) is crucial, especially for mounted plants.
​✨ Unique Features
​This orchid is a fascinating curiosity for collectors due to its "gregarious flowering" phenomenon. Plants in the same area (or collection) will often bloom simultaneously in response to a specific environmental trigger, such as a sudden drop in temperature after rain. The long-necked pseudobulbs give the plant an architectural, almost grass-like appearance even when not in bloom.
​🏷️ Specifications
​Plant Size: Recently deflasked and on small mounts
Plant Family: Orchidaceae
Plant Passport: A Dendrobium auricolor B 140084 C [buyer to use number of the plant label] D GB