A Midnight Revelation
In the lowland rainforests of New Britain, an island off Papua New Guinea, is an orchid that defied discovery for centuries. Bulbophyllum nocturnum grows as an epiphyte on trees at altitudes of 240–300 meters. Its existence was unknown to science until 2011, when Dutch botanist Ed de Vogel collected specimens from a logging concession area. Back in the Netherlands, the collected orchids presented a puzzle: their flower buds would form but then wither and die without ever opening.
The secret was only revealed when de Vogel took one of the plants home to observe it outside the lab. Around 10 p.m., two hours before midnight, a bud began to open. By morning, the flower had closed, and by 10 a.m., it had wilted completely. This brief, 12-hour life cycle is unique among the more than 25,000 known orchid species, making B. nocturnum the first and only one confirmed to flower exclusively at night. The species was formally described in the Botanical Journal of the Linnean Society by a team from the Royal Botanic Gardens, Kew, and Leiden University.
The flower itself is about 2 cm wide. It has yellowish-green sepals, a dark red lip, and greyish, hair-like appendages on its petals. These delicate structures are a characteristic of its subgroup, section Epicrianthes, known for its blooms.
The Pollinator Puzzle
The strictly nocturnal blooming of Bulbophyllum nocturnum presents an evolutionary question: why operate on a night schedule? Its pollinator likely involves pollinator, which remains unknown. While many other orchids use nocturnal moths for pollination, their flowers remain open during the day. B. nocturnum's strategy suggests a highly specialized relationship with a creature of the night.
The leading hypothesis suggests nocturnal midges or small flies. Scientists speculate that the flower's strange petal appendages mimic the appearance of certain fungi or slime molds, such as Arcyria and Stemonitis, that grow in the same habitat. These fungi are a food source for midges. The orchid may be tricking the insects into visiting by imitating their food, and in the process, the flies unwittingly transfer pollen. This form of deception is a common strategy in the Bulbophyllum genus, which is one of the largest of all flowering plants, containing around 2,000 species.
The discovery of B. nocturnum occurred in a logging area, which paradoxically enabled access for botanical survey while also representing a threat to the species' habitat. Due to threats from logging and agriculture, the IUCN has assessed the species' conservation status as Vulnerable.