Orchidaceae: Orchids

Family: Orchidaceae
Common name: Orchids

Orchids are the nobility of plant family! They have existed for millions of years on earth, they looks gorgeous and they are one of the two largest family of flowering plants, the other one being Asteraceae. There are over 28,000 species and over 100,000 hybrids spread all over the world in all kinds of climates and soils.

Most orchids are epiphytes growing on other trees; but there are orchids that grow in soil, rocks or grasslands. Regardless of the species, there are few characteristics that are specific to the family of Orchids:

  • bilateral symmetry of flowers
  • tiny seeds
  • resupinate flowers that turn about 180 degrees as they open, bending over backwards
  • labellum or modified lip petal that’s used as a landing pad for pollinators
  • fused stamens and carpels forming a column

The most common species of Orchids are Dendrobium, Cattleya, Pleurothallis, Oncidium, Epidendrum, Phalaenopsis and Bulbophyllum. Vanilla is one of the most famous Orchid plants that we all know about; vanilla essence made by soaking vanilla beans in alcohol and water to draw the essence from it.

Orchids come in a wide variety of sizes, shapes and colors; the smallest flower being 2mm and the largest about 3 meters. Orchids are also classified into monopodial, having a single upright stem reaching a height of several meters; and sympodial, with multiple stems growing laterally each stopping its growth after a certain length.

Most orchids are epiphytes with aerial roots that hang from the base of the plant absorbing moisture from the air through white spongy tips called velamen. Nutrition comes from minerals and other debris that’s collected near the dense roots of the orchid plants. Whereas terrestrial orchids form pseudobulbs that store water for long periods.

Orchids leaves are usually long and leathery with parallel veins; the texture and thickness of leaf depending on the weather and light-tolerance of the plant. Orchid flowers are extremely colorful and showy, with brilliant colors, patterns and markings to attract pollinating insects, bees and butterflies.

The flowers have a thick mass of pollen grains called pollinium stuck together with a gluey chemical. This sticks to the legs or body or pollinators who carry them to other flowers. But pollination is very rare, and most flowers stay unpollinated through their life time, though they live for many days, even weeks.

Once pollinated, they produce a capsule that contains over a million microscopic seeds which are dispersed by wind. Even with the large number of seeds, germination is very difficult since the seeds don’t have endosperm to provide them with nutrients.

The seeds have to fall on specific types of fungi which provide them with the nutrition required to germinate. Since this is very difficult, orchid seeds are germinated artificially in sterile growing environments, in a nutrient medium prepared with agar gel and carbohydrates the enable growth.

Orchid flowers are used in decorations, and is one of the biggest cut-flowers industries in the world. They are also used in making perfumes. The pseudobulb tubers are eaten raw, cooked or made into flour in some parts of the world. Orchids plants and flowers are also used in making beverages.

Orchid flowers also have some cultural significance with the flowers being used in various paintings and art forms. Many countries have adopted different species of orchids as their national flowers.

Propagation is through seeds or by root division, both methods quite difficult and time consuming.

Image credits: Tisa Sanoj, Shoy Jose

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