Habit and habitats

Habit and habitats

  • There are many orchids which are very beautiful belonging to different climatic zones and these cannot grow under the same climatic conditions.
  • India with a vast geographic expanse and climatic zones ranging from tropical to temperature supports a rich diversity of flora.
  • A vast majority of Indian orchids are confined to mountains where they are distributed from the base of hill to an elevation of 4,300m in climates ranging from tropical to temperate.
    Orchid Flower and parts

    • Flowers of orchids are perfect, terminal, solitary or in a spike or raceme or panicle
    • All orchids are made up of seven parts;
    • Three sepals, two petals, a lip or labellum, which is actually another petal, but showier than the rest; and a column enclosed in the trumpet like part of the lip.
    • The sepals and petals are typically coloured.
    • The sepals may be free from one another or sometimes united on occasion forming a definite tube, which is called sepaline tube.
    • The plant grows continuously in one direction only and their stems lengthen from one season to another and produce aerial roots along their whole length.
    • Each new growth produces its own set of roots.
    • They have more than one stem.
    • Sympodial orchid stems are generally thickened and bulbous are named as pseudobulbs
    • eg: Cattleya, Coelogyne, Epidenarum, Laelia and Sophronitis.
    • The roots of epiphytic orchids are very curious, they are covered by a whitish spongy and pulpy coat called vellamen.
    • Rhizomes are fond only in sympodial types of orchids and are actually a primary stem, from which arises the secondary stem.

    II. Based on their habitats, orchids fall under 5 classes
      (i) Terrestrial (or) Ground Orchids
      • Grow in soil, Sympodial and perennial
        • Example : Spathoglottis plicata, Arundina graminifolia, Phaius tankervilleae, Cymbidiums,Paphiopedilum
      (ii) Epiphytic Orchids
      • Grow well on other plants
      • Abundant in humid tropical rain forests of India. - Elevation upto 3000m.
        • Example : Vanda, Vanilla, Dendrobium, Cymbidium, Cattleya, Oncidium etc.
      (iii) Saprophytic Orchids
      • Live on dead and decaying organic matter, - Found on the moist forest floors.
        • Example : Neottia, Galeola, Listera etc.
      (iv) Lithophytic Orchids
      • Rarely found and they grow in moist, shaded rocks and crevices of walls.
        • Example : Cymbidium munronianum, Diplomeris birsuta
      (v) Subterranean Orchids
      • Underground orchids, - Found in Australia
        • Example : Rhizanthetta and Cryptanthemis
    III. Classification based on Temperature requirement
  • For growing purposes, orchids are usually divided into three temperature groups.
      1. Warm orchids : 15.5oC
        Eg. Phalaenopsis, Vanda, Rhynchostylis and some Dendrobium species.
      2. Intermediate Orchids : 13oC to 18oC
        Eg. Cattleya, Laelia, Brassavola, Oncidium, Miltonia, etc.)
      3. Cool Orchids : 10oC to 13oC
        Eg. Cymbidium, plain leaf Paphiopedilum, some species of Miltonia, Odontoglossum and Dendrobium.
  • orchid
Last modified: Wednesday, 20 June 2012, 10:05 AM