Dendrobium convexum, commonly known as the piggyback orchid,[1] is an epiphytic orchid in the family Orchidaceae. It has a creeping, brittle root, erect pseudobulbs with a single leaf on the top and one or two cream-coloured, short-lived flowers with a red and yellow labellum. It is native to Southeast Asia, New Guinea and tropical North Queensland, Australia.
Dendrobium convexum is an epiphytic herb with a brittle root about 3sigfig=1NaNsigfig=1 thick creeping over the surface of rough-barked trees. Shiny pseudobulbs NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide arise at well-spaced intervals along the root, each on a thin stalk about 10sigfig=1NaNsigfig=1 long. There is a single dark green leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=2NaNsigfig=2 wide on the end of the pseudobulb. One or two cream-coloured flowers NaNsigfig=2NaNsigfig=2 wide appear at the base of the leaf on a pedicel 5sigfig=1NaNsigfig=1 long. The dorsal sepal is NaNsigfig=2NaNsigfig=2 long and about 4sigfig=2NaNsigfig=2 wide. The lateral sepals are NaNsigfig=2NaNsigfig=2 long and the petals are linear, NaNsigfig=2NaNsigfig=2 long and about 1sigfig=1NaNsigfig=1 wide. The labellum is yellow with a red centre, about 11sigfig=2NaNsigfig=2 long and 4sigfig=1NaNsigfig=1 wide and has three lobes. Flowering occurs sporadically and the flowers open for less than a day.[2] [3] [4]
The piggyback orchid was first formally described in 1825 by Carl Ludwig Blume who gave it the name Desmotrichum convexum.[5] He published the description in his book Bijdragen tot de flora van Nederlandsch Indië.[5] [6] In 1831, John Lindley changed the name to Dendrobium convexum.[7] The specific epithet (convexum) is a Latin word meaning "arched outward" or "protuberant".[8]
Dendrobium convexum grows in mangroves, humid areas of scrub, forest and rainforest mainly on rough-barked trees. It occurs in Malaysia, Thailand, Indonesia, New Guinea and on the Cape York Peninsula as far south as Innisfail, Australia.