The Orchid Family

The Orchidaceae (orchids) is one of the three largest families of flowering plants.  Orchids vary in color, fragrance and size.  They can be found on the ground (terrestrials), on rocks (lithophytes) and on trees (epiphytes).  Terrestrial orchids are widely distributed in all habitats while epiphytes are found mainly in tropical habitats.

Two basic types of orchids are:

1.      sympodial – orchids characterized by individual shoots with limited growth;  examples – cattleyas and paphiopedilum

2.      monopodial – orchids characterized by shoots with unlimited growth:  examples – vandas and phalaenopsis

Orchid Structure

Leaves

            Leaves can be tough and leathery OR thin and flexible.  They can have a single fold at the midline or be pleated with several prominent veins, round in cross-section or laterally flattened.  The major veins or the orchid are usually parallel.  Some leaves can be mottled or iridescent making the foliage very attractive.

Roots

            Roots or epiphytic orchids have an epidermis velamen that is specialized for the protection of interior tissues from water loss and for water and mineral uptake.

Flowers

            The structure of orchid flowers creates stunning beauty.  There is an out whorl of similar segments called petals.  The lower petals specialize to form the often chief attractive feature of the flower and are known as the “lip” or Lavellum”.  The center of the flower is the column which contains a fusion of the stamens and pistil.  Variation among this flower structure is what creates the unique characteristics of the orchid flower.