ORCHID

Some orchids, like Neottia and Corallorhiza, lack chlorophyll and are unable to photosynthesise. Instead, these species obtain energy and nutrients by parasitising soil fungi through the formation of orchid mycorrhizas. The fungi involved include those that form ectomycorrhizas with trees and other woody plants, parasites such as Armillaria, and saprotrophs These orchids are known as myco-heterotrophs, but were formerly (incorrectly) described as saprophytes due to the belief that they gained their nutrition by breaking down organic matter. While only a few species are achlorophyllous holoparasites all orchids are myco-heterotrophic during germination and seedling growth and even photosynthetic adult plants may continue to obtain carbon from their mycorrhizal fungi.
A majority of orchids are perennial epiphytes, which grow anchored to trees or shrubs in the tropics and subtropics. Other species are lithophytes, growing on rocks or very rocky soil, or are terrestrial. Nearly all temperate orchids are terrestrial.
The leaves of most orchids are perennial, that is they live for several years, while others, especially those with plicate leaves, shed them annually and develop new leaves together with new pseudobulbs, as in Catasetum.
The cells of the root epidermis grow at a right angle to the axis of the root to allow them to get a firm grasp on their support. Nutrients mainly come from animal droppings and other organic detritus on their supporting surface.
"When all the blooms on your orchid plant have faded, cut off flowering stem about an inch from the base, or as close to the base you can easily get to."Use a sharp knife and cut the stem at an angle—that's it!
A old flower stem can be seen to the right on this phalaenopsis. As you can see, a clean cut was made about an inch from the base of the plant. Two new flowerspikes can be seen to the left. Once these have finished flowering, they will be cut off just above the first node from the base of the plant. The nodes are encased in a lighter colored sheath that looks like a white band
Phalaenopsis can often be rebloomed from 'just-bloomed' spikes by going down to the first node below the lowest bloom on the spike, and cutting the spike off about 0.5" above this node. This should only be done on strong robust plants, if at all.