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Dendrobium sp. Sw. 1799
pronounced: den-DROH-bee-um species
(Orchidaceae – the orchid family)
common name: Dendrobium
Dendrobium is from the Greek δενδρον (dendron), a tree, and βιος (bios), life – life on a tree, i.e. epiphyte.
The genus is a huge one, having been established in Stockholm, Sweden, in 1799 by Olof Swartz. Swartz (1760–1818) was a Swedish botanist and taxonomist, best known for his taxonomic work and his studies into pteridophytes. He was the first specialist in orchid taxonomy, and classified the 25 genera that he recognized through his own work. He was also the first to realize that most orchids have only one stamen, while slipper orchids have two. The genus Swartzia in the Fabaceae family was named in his honour. The Dendrobium genus today contains about 1,200 species, occurring in diverse habitats throughout much of south, east, and south-east Asia, including the Philippines, Borneo, New Guinea, the Solomon Islands, Australia and New Zealand. There is much reclassification of Dendrobium in progress, especially in Australia. The Winika orchid from NZ was formerly Dendrobium cunninghamii, but has now been moved into a monotypic genus, Winika. The Dendrobium speciosum complex was upgraded in 1989 into individual species, and the Dendrobium bigibbum complex (which contains the Cooktown Orchid, Dendrobium phalaenopsis) has recently been split up.
In some species of Dendrobium the short ovate leaves grow alternately over the whole length of the stems, while in others the leaves are bunched towards the apex of the stem. The axillary inflorescences vary in length from insignificant to 1 m long, and can carry from 3 or 4 to as many as 100 flowers. Deciduous species carry their leaves for 1–2 years, then typically flower on leafless canes, while canes of evergreen species usually flower in their second year and can continue to flower for a number of years.
These orchids grow quickly throughout summer, but take a rest during winter. Dormant buds erupt into shoots from the base of the pseudobulb mainly in spring, and a few species in autumn. This is then followed by rapid growth of new roots. Reproduction is usually through seed, but a few species reproduce asexually through keikis produced along the stem, usually after flowering and sometimes as a result of injury to the growing tip. If a new plant is desired, the keiki should be left on the mother plant until it develops a healthy root system and has 2 or 3 leaves or canes, at which point it can be carefully removed with a sharp knife (cut below and above the stem, leaving a small piece of stem on the baby plant) and planted in its own pot. If a new plant is not desired, the keiki can be removed at any time. Removing the entire inflorescence after flowering is completed can prevent the production of keikis and result in a tidier appearance of the plant.
The beautiful orchid pictuted on the right is Dendrobium (Rinnapa x Diamond Queen) 'Hawaii'.
Photographs taken in Picnic Bay 2011
Page last updated 3rd April 2017