Download Orchids : The Defined Beauty of Nature on Earth Theophrastus, the

Orchids : The Defined Beauty of Nature on Earth
Theophrastus, the father of botany (370 -285 BC) named “ORCHIDS” on the basis of the
resemblance of paired underground tubers to masculine anatomy (the testes). They shows
fascination for their beautiful flowers. They represent to the family Orchidaceae, the most
highly evolved family among monocotyledons with 600 to 800 genera and 25,000-35,000
species in the world. They are peculiar and are highly valued in the international market.
Majorly orchids are are native to tropical countries, like America, Asia and Australia.
In India, they constitute 9% of our flora and are generally homed to Himalayas, and to some
extent at Eastern and Western Ghats. About 1,300 species of about 190 genera are found in
India. Brazilian Cattleyas, Mexican Laelias and Indian Dendrobiums, Cymbidiums and
Vandas played a major role in the development of modern orchid industry in the world.
Orchids can be divided into two groups - monopodial (plants grows every year with a
single stem) and sympodial (plants produces every year a new shoot) depending upon their
habit of growth. On the basis of climatic requirements, they are grouped as:
1. Tropical orchids.
2. Subtropical orchids (800-1850 m altitude) Eg. Phaius, Coelogyne, Cymbidium,
Dendrobium, Calanthe etc.
3. Temperate orchids. (1850-3500 m altitude) Eg. Pleione, Paphiopedilum, Satyrium,
Cymbidium, Hervinium etc.
4. Alpine orchids (3500-5000 m altitude) or ground orchids.
Morphologically orchids are perennial herbs with simple leaves. The specialized flower
structure conforms to a standard plan, the vegetative parts shows great variation, i.e. may be
epiphyte, terrestrial, saprophytic or leafless in nature. Epiphytic orchid plants can be
cultivated on live Trunks or branches. Eg. Vanda tessellate, Wooden Blocks, or baskets and
bamboo-splits, as well as in pot or bed.
Orchids have bilaterally symmetrical (Zygomorphic) flowers with an inferior ovary.
Among all petals, the 3rd petal is labellum or the lip. It helps in attracting and supporting
the pollinating insect and is responsible for different names like `Frog orchid', `Dove
orchid', `Spider orchid', `Lady slipper orchid' etc. The reproductive organs, stamens and
pistil, are condensed and forms a consolidated complex body, the „column', both part being
separated by a flap or projection called rostellum. Each flower has one, two or rarely three
stamens. Their pollen grain coheres in the pollinia. Orchids are generally propagated by offshoots, splitting, back-bulbs, top-cuttings, seed culture and tissue culture. Hybridization is
generally performed by pollination.
The most interesting and adaptive feature of the family Orchidaceae is the physiology
of its seed germination. Orchid seeds are exceedingly small, dust like and are produced in
very large numbers i.e. 1,300 to 4,00,000 seeds per capsules. Their colour and shape varies.
Under natural conditions, their seed germinates after being infected by fungus, the orchid
mycorrhiza (coined by Frank in 1885) and mostly belongs to a non-sporing group
Rhizoctonia. In Japan 54 different fungi were isolated from 20 orchid species. Utmost care is
required during their cultivation. It all depends depends on local climatic conditions like high
rainfall and relative humidity other than macro and micronutrients, favours orchid growth.
Water stagnation and direct sunlight with high intensity retards their distribution. This may be
the reason for their high endemism.
Some ornamental indian species: Aerides crispum, A. fieldingii, A. multiflorum, A.
odoratum, Anaectochilus roxburghii, Arachnis clarkei, Arundina graminifolio, Bulbophyllum
leopardinum, Calanthe masuca, Coelogyne elatn, C. devonianum, Cymbidium pendulum, C.
longifolium, C. munronianum, Dendrobium aggregatum, D. aphyllum, D. fimbriatum, D.
jenkinsii, D. moschatum, D. nobile, Paphiopedilum faireanum, P. venstum, P. hirsutissium, p.
insigne, Phaius wallichii, Pleione praecox, Rhynchostylis retusa, Thunia alba, Vanda
cristata, and V. coerulescens.
ORCHIDS WITH MEDICINAL IMPORTANCE
In India, orchids are employed for a variety of therapeutic use in different systems of
traditional medicines like Ayurveda, Siddha and Unani. Some are mentioned as follows:
Species
Disease
Acampe praemorsa
Rheumatism
Habenaria's
Unconsciousness, vermicide and as blood purifier
Cymbidium aloifolium
Emetic and purgative
Dendrobium ovatum
Stomach ache
Eulophia nuda
Tumors and bronchitis
Flickingeria nodosa
Astringent, aphrodisiac, expectorant
Luisia zeylanica
Emollient for boils, abscess and burns
ORCHIDS EXPLOITATION
Of the world's 30,000 orchid species, some 10% (3,000) are believed to be endangered in
their native habitats due to the physical destruction of habitat and over-collection. An
example is Paphiopedilum druryi, found in Agastaya Hills in South India, is now difficult to
locate.
CONSERVATION OF ORCHIDS
The convention of International Trade in Endangered Species of Fauna and Flora (CITES),
ratified by India, places all species of Orchidaceae under Appendix II, meaning that their
trade will be only through export permits. Steps have also been taken to conserve Indian
native species by establishing Orchidaria, sanctuaries and germplasm conservation centres.
Botanical survey of India has established Orchidaria at Shillong and Yercaud to conserve rare
and endangered species. In Sikkim orchid sanctuaries at Singtom and Deorali and in
Arunachal Pradesh at Tapi are established.
Orchids are currently the second most valuable potted crop. The largest exporters of
potted orchids include Taiwan, Thailand, the United Kingdom, Italy, Japan, New Zealand
and Brazil, while the largest importer of potted orchids is the United States.
To recognize the global importance of orchids as potted flowering plants, an orchid
research program was initiated at Michigan State University with a goal to elucidate the
flowering requirements for several orchid species and to use this information to develop
necessary production protocols for commercial growers.
Similar to other potted plants, flowering orchids are much more marketable and
commercially valuable than plants without flowers. They can be stored at low temperature
upto 00. However, scientific research on orchid growth and development has been limited to a
few species and commercial production information is only available for hybrids of the genus
Phalaenopsis. Research has been conducted on many economically important floriculture
crops such as chrysanthemums, Easter lilies, and poinsettias and production schedules have
been developed. Although orchids are one of the most commercially valuable flowering plants
in the world, with some notable exceptions (e.g., Phalaenopsis and Cymbidium), knowledge
of the flowering process for the vast majority of species is unknown. Limited scientific
research has been performed on controlled greenhouse production. Common growing
temperatures range from 10 to 29 °C (50 to 84 °F).
The primary goal of orchid research program is to understand how environmental
parameters (e.g. temperature and light) influence growth and development of species. The
new techniques will be developed to disseminate the production schedules to commercial
growers, which will allow orchids to be produced in controlled greenhouses in a uniform
manner.
In addition to our stated research objectives, there is flexibility to research and focus
on other aspects of orchid production, such as nutrition, postharvest handling, marketing, and
pest management.