Orchids: Dendrobium phalaenopsis
Whereas the preceding dendrobium is a cool-loving species this orchid is quite the opposite. The cutare often seen at the florist’s, though they may differ in colour from the illustration, for the type species is extremely variable, ranging from white to dark velvety violet-purple.
Dendrobium phalaenopsis is indigenous to New Guinea, Timor and Queensland, in other words to regions that are definitely tropical. Its principal requirements in cultivation are ample heat and moisture, particularly atmospheric moisture, and so it can be grown successfully in the home in a large aquarium or above a paludarium, where it is also exposed to sunlight. Syringing will also provide the atmospheric moisture. In winter it must have a brief period of rest when the temperature need not be lowered but watering should be greatly limited.
The pseudo-bulbs of D. phalaenopsis are erect, firm, and topped by several non-deciduous or only partly deciduous leaves. The first flower clusters (panicles) grow from the top of the pseudo-bulb, later flowering is one level lower, from the axils of the leaves. Flowers are produced even by old, leafless pseudo-bulbs that have flowered in preceding years. In the wild this species grows as an epiphyte or on the ground. The compost and method of propagation are more or less the same as for the previous species.
As one can see from these two examples, species of the same genus may have entirely different requirements as regards environment. This is not at all surprising, for the genus Dendrobium includes some 1,500 species and is one of the largest groups of orchids (two others are Pleurothallis and Bulbophyl-lum). That is why when growing these plants it is always important to refer to specialized literature which not only gives the basic requirements for the successful cultivation of individual species, but also various ‘special hints’.