Orchid family
Description
One of the most specialized families of monocotyledonous plants, occurring all over the world, but with its largest diversity in the tropics (Orchidaceae 1).
Orchids are perennial herbs with rhizomes or tubers, sometimes epiphytic with long pendant roots which absorb moisture from the air, especially in the tropics. The leaves are simple, entire, parallel veined, often fleshy. The flowers are borne in variable inflorescences, irregular, with 3 sepals and 3 petals of which one is usually enlarged into a labellum, which is different from the other two and usually with a conspicuous colouration. Most often there is only 1 anther, borne with the stigma on a column in the centre of the flower. This complex structure is concerned with the various pollinator species. The ovary is inferior. The fruit is variable and contains large numbers of very small seeds.
There are about 750 genera.
Use
Many species are cultivated for their flowers. The genus Vanilla yields the flavouring vanilla.
Described species
Vanilla fragrans, vanilla