Orchids have several growth forms such as terrestrial, epiphytic and some are lithophytic. About 70% of the world's orchids are epiphytic. The majority of temperate orchids are terrestrial while tropical orchids are epiphytic or lithophytic. Epiphytic orchids grow and attach themselves to host trees or small twigs at the top of the tree canopy. Epiphytes usually have a strongly developed root system and expose them to the air or crevices and bark of the host tree to absorb moisture and nutrients. Terrestrial orchids grow in the humus or leaf litter of the forest floor and can adapt to a variety of growing conditions like swampy ravines, moist forest floors, sand dunes, and even semi-arid desert soils. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay Terrestrial orchids form tubers in the soil and use their underground roots to obtain nutrients from the soil. Terrestrial orchids have deciduous flowers and leaves that drop during the winter. Lithophytic orchids grow on exposed rocks. The leaves of the lithophyte orchid generally appeared fleshy. Roots burrow into crevices to receive water and nutrients from rainwater, surrounding moss and organic debris. Lithophytic orchids have pseudobulbs that can store water to help the plant survive during periods of drought. Growth Cycle and Growth Pattern of the Orchid An alternating cycle of growth periods and rest periods controls the life of the orchid. By exposing them to too much humidity during the dormant period, the orchids will not flower and will only form weak shoots. The growth pattern of orchids can be divided into monopodial and sympodial. Monopodial orchids grow on a single central stem with leaves on either side, while sympodial orchids feature multiple growths and usually put out one or more new shoots per year. Each new growth comes from the side of this one and in a circular pattern. Dendrobium (subfamily: Epidendroideae) is one of the most popular genera of Orchidaceae, with approximately 1,523 species worldwide. Dendrobium belongs to the epiphytic sympodial orchid, recognized by Olof Swartz in 1799. Dendrobiums are distributed in tropical regions where annual precipitation is high and without much seasonal variation throughout the year. Dendrobiums are native to Southeast Asia and are found in a variety of habitats except the coldest, driest regions. The life cycle of Dendrobium orchid includes flowering phase, growth phase and dormancy. They grow rapidly from summer to fall and remain dormant during the winter. New shoots will form and begin to flower in spring. Dendrobiums can be divided into evergreen and deciduous. Evergreen Dendrobiums flower on new growth, have cane-shaped stems and papery green leaves, bear the flowers in erect panicles and singly at the nodes. Deciduous dendrobiums bloom on old canes, drying and shrivelling like bamboo canes after the leaves fall. Dendrobiums do not use the host's food supply because they have a specialized root structure to absorb water and accommodate mycorrhizal fungi for nutrients. Some stems (pseudobulbs) are green andsucculent while others are long, thin, swollen and fibrous. Dendrobium flowers are small to medium sized with a narrow lip or no side lobes. Some Dendrobiums can self-pollinate and others are pollinated by insects. Dendrobiums will produce capsule fruits and very small seeds with a spherical ovoid embryo inside each seed. Dendrobium needs a lot of light to grow well and about 75% of sunlight is needed for the plant to grow. Dendrobium can withstand direct sun early in the morning or evening but requires shade between 11 a.m. and 3 p.m. when light intensity is too high. Optimal light will produce healthy, attractive flowers while a deficit of light will result in dark green leaves. Yellowish or brownish leaves with spots on the underside represent sunburn. Dendrobium grows best at night temperatures between 15-18ºC and daytime temperatures between 23-29ºC. About 50-75% humidity is needed for Dendrobium and excessive humidity will cause fungal and bacterial infection. Infection can be reduced by circulating air to cool the plant. Aeration is important to maintain the health of the orchid and dry out excess moisture. Dendrobiums prefer rainwater and are watered once a week. The roots are very sensitive and rot easily. So, dendrobiums are always rewatered once the soil is dry. Commercial Value and Market Demand of Orchid Orchid cultivation began in 500 BC and is used for ornamental and medicinal purposes. The flowers they produce are extremely exotic and attractive, with curious shapes, varied colors and a longer lifespan, making them one of the top ten "cut flowers" in the international flower market. Orchids are commonly used as cut flowers and potted plants. Their demand is huge and their prices are high in the global floriculture market due to several properties. Cattleya Labiata is the most popular orchid species and is known as the "Queen of Orchids" for its colorful appearance and wonderful aroma. Cattleya is widely used in brooch accessories and floral decorations. Due to the small size of the flowers, the Cymbidium orchid is also used as a brooch accessory. Their tall stems, long leaves, and long-lasting aroma make them one of the top choices for orchid lovers. Dendrobium, with its wide variety of colors and shapes, is in high demand in the international floriculture market. Miltonia orchids have large flowers which make them ideal for bouquets and perfumes as well as indoor flowers. Phalaenopsis is known as the “moth orchid” because its flowers resemble a flying butterfly. For most beginners, these plants are the preferred orchids because they can tolerate many conditions. Vandas is known as the "Singapore orchid" and is primarily native to Southeast Asia. Their flowers bloom in different colors and their stems are long. The Vandas can be placed in the hanging basket. Orchids have been widely used in traditional Chinese medicine. Many orchids have been proven to have medicinal properties. Medicinal orchids mainly belong to the genera: Calanthe, Coelogyne, Cymbidium, Cypipedium, Dendrobium, Epthemerantha, Eria, Galeola, Gastrodia, Gymnadenia, Habenaria, Ludisia, Luisia, Nevilia and Thunia. Orchids contain phytochemicals such as alkaloids, flavonoids, carotenoids, anthocyanins, sterols,.