Structural Adaptations of Orchids

Orchid Types

• The orchid has adapted seeds, roots, stems and leaves that allow the plant to survive in a variety of ecosystems. Epiphytic orchids grow by clinging to a tree's branches. The orchid does not hurt the tree, but simply uses it to reach sunlight. Terrestrial orchids spread their roots across and into the soil. Lithophytic orchids wrap their roots around rocks. A rare species, lithophytic orchids are rarely cultivated as a house plant or in the greenhouse

Roots

• The roots of the epiphytic orchid help to anchor the plant securely to the tree. The roots do not penetrate the trees bark, but simply cling to branch's surface by wrapping around it. The roots of terrestrial orchids cling to surface organic debris and soil. The roots of the lithophytic orchid secure the plant to rocks, cliffs and crevices. Orchid roots readily absorb the rainwater and store it in their fleshy cells. The roots help the plant survive during times of drought. As the plant uses the root's water supply, the roots take on a shriveled appearance. When it rains, the roots flesh out as they absorb the water and begin storing it. The roots readily absorb sunlight and nutrients to support the orchids needs.

Leaves and Pseudobulbs

• The leaves of the orchid work to photosynthesize sunlight, also to store water. They have a fleshy succulent appearance. The leaves have the ability to feed by using the air and absorbing nutrients from the rainwater that runs down off trees, foliage and other surfaces. During the humid night, the leaves also absorb and store carbon dioxide. The orchid uses the carbon dioxide during the day for better photosynthesis, according to the Mary Shelby Botanical Garden's website. The leaves of the terrestrial orchid usually die to the ground during the heat of summer, but the plant reemerges from the remaining roots in the fall. Some orchids also have pseudobulbs. Foliage and flower stems all emerge from the pseudobulb of the plant. Pseudobulbs work as storage reservoirs for water and nutrients.

Seeds

• All orchids produce lightweight seeds, which the wind, can easily pick up and scatter. The seeds contain no endosperm.. Endosperm is the nutrients that help seeds grow. Despite the lack of endosperm in the orchid seed, it has adapted itself to utilize mycorrhizal fungi. The fungi penetrate the seed and help the seed develop. The fungus provides all the nutrient the seed requires germinate and produces a young plant. Once leaves and roots emerge, the orchid no longer relies on the mycorrhizal fungi. The seeds of the orchid cannot germinate without the aid of the fungi, according the Brisbane Orchid Society's website. The lack of endosperm inside the seed also makes it lighter so the wind can carry the seed a greater distance.