From Wikipedia, the free encyclopedia
is a genus in the orchid family (Orchidaceae
) which, although not large (about fifty species), is one of the most important florally. This genus and it allies are considered to be the most highly evolved of all orchids within Orchidaceae. The genus is very highly prized in horticulture for its showy, fragrant, long lasting, and intensely colorful flowers.
The name "Vanda" is derived from the Sanskrit name for the species Vanda tessellata.
These mostly epiphytic, but sometimes lithophytic or terrestrial orchids are distributed in India, Himalaya, SE Asia, Indonesia, the Philippines, New Guinea, southern China and northern Australia.
The genus has a monopodial growth habit with leaves that are highly variable according to habitat. Some have flat, typically broad, ovoid leaves (strap-leaves), while others have cylindrical (terete), fleshy leaves and are adapted to dry periods. The stems of these orchids vary considerably in size; there are miniature plants and plants with a length of several meters. The plants can become quite massive in habitat and in cultivation, and epiphytic species possess very large, rambling aerial root systems.
There are few to many flattened flowers growing on a lateral inflorescence. Most show a yellow-brown color with brown markings, but they also appear in white, green, orange, red and burgundy shades. The lip has a small spur. Vandas usually bloom every few months and the flowers last for two to three weeks.
Many Vanda orchids (especially Vanda coerulea) are endangered, and have never been common because they are usually only infrequently encountered in habitat and grow only in disturbed forest areas with high light levels, and are severely threatened and vulnerable to habitat destruction. The export of wild-collected specimens of the Blue Orchid (Vanda coerulea) and other wild Vandas is prohibited worldwide, as all orchids are listed on Appendix II of the Convention on International Trade in Endangered Species.
This genus is one of the five most horticulturally important orchid genera, because it has some of the most magnificent flowers to be found in the entire orchid family. This has contributed much to the work of hybridists producing flowers for the cut flower market. Vanda coerulea is one of the few botanical orchids which can produces varieties with blue flowers (actually a very bluish purple), a property much appreciated for producing interspecific and intergeneric hybrids.
The color blue is rare among orchids, and only Thelymitra crinita, a terrestrial species from Australia produce flowers that are truly "blue" among the orchids, the other being Aganisia cyanea, a lowland species from Northern South America that is difficult in cultivation, but has metallic blue flowers. Both of these species, much like Vandas, also have a bluish purple tint towards the inner petals of the flowers.
Vanda dearei is one of the chief sources of yellow color in Vanda hybrids. Vanda Miss Joaquim, a terrestrial Vanda variety and natural hybrid with terete (cylindrical) leaves, is the National Flower of Singapore.
The plants do not possess pseudobulbs but do possess leathery, drought resistant leaves, and some varieties terete leaf forms. Almost all of the species in this genus are very large epiphytes that are found in disturbed areas in habitat and prefer very high light levels, and the plants have large root systems. Some of these species have a monopodial vine-like growth habit, and the plants can quickly become quite massive.
These plants prefer consistent conditions day to day in cultivation to avoid dropping their bottom leaves. The epiphytic species are best accommodated in large wooden baskets bare root, which allows for the large aerial root systems. Disturbing or damaging the roots of large, mature Vandaceous orchid plants, and in particularly, Vanda and Aerides species can result in the plants failing to flower and going into decline for a season or more. These plants do not tolerate disturbance or damage of their root systems in cultivation when they become mature. The terete leaved terrestrial species are very easy to cultivate.
When grown bare root, the epiphytic species require daily watering and weekly feeding and are very heavy feeders in cultivation. They can be grown out of doors in areas like Hawaii provided they are given some shade. The key to successfully cultivating epiphytic Vanda species are consistent growth conditions. The plants are singularly intolerant of fluctuating environmental conditions or watering regime in cultivation, and results in the plants dropping lower leaves and having a haggard, straggling appearance and going into decline. The epiphytic Vanda species are not plants for beginning orchid enthusiasts and usually require a controlled growing environment to achieve some measure of success in cultivation.