The Orchidaceae is one of the largest families in the plant kingdom with about 28,000 currently accepted species in about 763 genera. The family is distributed worldwide except for the polar regions, and members of the family range from small terrestrial species to moderately large epiphytic species in the tropic. Like most monocots orchids generally have simple leaves with parallel venation. The flowers are often complex in design and colouration and may be borne as individual flowers or in racemose inflorescences, which may be large. The flowers comprise two whorls of sterile parts, the outer whorl of three sepals and the inner whorl of three petals. The pollen is shed as single grains in a few of the subfamilies but in the majority of orchids the anther has two pollinia which are waxy masses of pollen with a sticky pad to adhere to the pollinating insect. The seeds of orchids are very small and lack endosperm and must enter a symbiotic relationship with a mycorrhizal basidiomycetous fungus to germinate, so all orchids are mycoheterotrophic at least during germination. However some species such as Limodorum abortivum, the Purple Limodore remain mycoheterotrophic throughout their life cycle and completely lack leaves or chlorophyll, relying on the relationship with the fungus for nutrition.
Tiger Orchid in Thailand
epiphytic Dendrobium in Malaysia
Slipper Orchid in China
Purple Limodore in Greece
Bee Orchid in Greece