Bulbophyllum nocturnum was recently discovered on the island of New Britain (part of Papua New Guinea) and is the first known orchid with flowers that consistently open at night and close during the day.
Bulbophyllum nocturnum flower (Photo: André Schuiteman)
Bulbophyllum nocturnum J.J.Verm., de Vogel, Schuit. & A.Vogel
Data deficient (DD) according to IUCN Red List criteria.
Epiphytic in rainforests between 240 and 300 m above sea level.
About this species
With some 25,000 known species, orchids (Orchidaceae) make up the largest plant family. Their flowers show a tremendous range of variation in size, colour and shape. Some last for months, whereas others are open for only a few hours. Until the discovery of Bulbophyllum nocturnum, no truly night-flowering orchid species was known, that is to say, one that consistently opens its flowers after dark and closes them during the day.
Geography and distribution
Only known from the island of New Britain, Papua New Guinea.
Discovery of the night-flowering orchid
In 2008, Ed de Vogel from NCB Naturalis in Leiden, The Netherlands, brought back a small orchid that he had collected on the remote and little explored island of New Britain during one of his expeditions to Papua New Guinea. When cultivated at the Hortus Botanicus, Leiden, the plant readily produced flower buds, but these all seemed to abort just before opening. It was only when the plant was observed during the night that it was discovered this species has flowers opening around 10pm and closing some twelve hours later. It was also found that each flower opens only once.
This species was described in 2011 as Bulbophyllum nocturnum and may well be called the first night-flowering orchid, although some growers report that another species, Dendrobium amboinense, may open its flowers just after midnight and close them well before noon (although others report that its spectacular flowers open at dawn).
An epiphytic orchid with pendulous, stem-like rhizomes up to 15 cm long. Its leaves are relatively broad, about 5–6 by 2–3 cm. The inflorescences are short and carry only a single flower. The flowers are about 2.5 cm across, open widely and have no noticeable scent. The rather narrow sepals (the three outer segments of the flower) are yellowish green and lightly spotted red at the base. The petals are small with several light grey pendulous appendages that are rod-shaped, papillose (minutely warty) and up to 8 mm long. The small lip is dark red. The flowers last about 12 hours and open around 10pm.
Bulbophyllum nocturnum is a member of section Epicrianthes of the Bulbophyllum genus. In most respects it is a fairly average member of this section in that the flowers are rather small but at the same time unusual, if not to say bizarre. These bulbophyllums stand out from most other orchids in that the appendages of the petals look like small sausages, hairy spider legs, tiny, heart-shaped balloons or minute fungi. These appendages often cause the flowers to resemble small animals, and this has made some botanists speculate that they are pollinated by insects looking for a mate or prey. However, Kew botanist André Schuiteman, one of the co-authors of this species, considers it more likely that the flowers mimic fruiting bodies of slime moulds (Myxomycota) and thinks that the pollinators are probably tiny fungus gnats. Only field studies can determine which hypothesis is right.
Night-flowering orchid makes Arizona University’s top 10 new species list
In May 2012, Bulbophyllum nocturnum was chosen by the International Institute for Species Exploration at Arizona State University and a committee of scientists from around the world as one of the Top 10 new species described in 2011. Members of the international committee, who made their selection from more than 200 nominations, were looking for species that captured their attention for being unusual or having traits that are bizarre.
Other new species shortlisted were a sneezing monkey, a beautiful but venomous jellyfish, a walking cactus and a fungus named after a popular TV cartoon character. The full list of species is available on the Arizona State University website.
Threats and conservation
Bulbophyllum nocturnum is not of any great horticultural interest for collectors but may be threatened by logging of the lowland rainforest in which it occurs, especially as it is so far only known from a single plant. This suggests that it is probably not widespread in the wild; however, New Britain is as yet too poorly explored botanically to be certain.
In the Hortus Botanicus, Leiden, this species has proved easy to cultivate in a warm greenhouse, along with other tropical lowland orchids. The plant is grown on a slab of compressed coconut fibre, kept in light shade and watered regularly by spraying all year round.
This species at Kew
So far no living specimen is present at Kew.
An alcohol-preserved specimen of Bulbophyllum nocturnum is held in Kew’s Herbarium, where it is available along with numerous other orchid specimens to researchers from around the world by appointment. The details of some of these can be seen online in the Herbarium Catalogue.
Schuiteman, A., Vermeulen, J.J., de Vogel, E. & Vogel, A. 2011. Nocturne for an unknown pollinator: first description of a night-flowering orchid (Bulbophyllum nocturnum). Botanical Journal of the Linnean Society 167: 344-350.
Kew Science Editor: André Schuiteman
Copyediting: Nicola Merrett
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