Orchid stems are also specialized into what are called pseudobulbs. These are basically expanded stems that allow the plant to store excess water and food. The roots of epiphytic (tree-dwelling) orchids have a special outer layer of dead cells called velamen. Because orchids metabolize slowly in order to not outpace their resources, the roots also absorb slowly, meaning that they need help catching water as it passes by. The velamen cells catch and fill with water as it passes by so that the true root (the core of the root structure) has ample time to access as much water as it can. Velamen is silver-white in color, but becomes transparent when wet, so that when the root is wet it turns green as you are able to see through to the inner structures of the root that contain chlorophyll.
Like most monocots, orchids generally have simple leaves with parallel veins, although some Vanilloideae have reticulate venation. Leaves may be ovate, lanceolate, or orbiculate, and very variable in size on the individual plant. Their characteristics are often diagnostic. They are normally alternate on the stem, often folded lengthwise along the centre ("plicate"), and have no stipules. Orchid leaves often have siliceous bodies called stegmata in the vascular bundle sheaths (not present in the Orchidoideae) and are fibrous.
Using the molecular clock method, it was possible to determine the age of the major branches of the orchid family. This also confirmed that the subfamily Vanilloideae is a branch at the basal dichotomy of the monandrous orchids, and must have evolved very early in the evolution of the family. Since this subfamily occurs worldwide in tropical and subtropical regions, from tropical America to tropical Asia, New Guinea and West Africa, and the continents began to split about 100 million years ago, significant biotic exchange must have occurred after this split (since the age of Vanilla is estimated at 60 to 70 million years).
Some people have very responsibly done research before watering their plant and are confused by recommendations they’ve found elsewhere that say to use only water at room temperature. Here at Just Add Ice Orchids, we love orchids and have tested our theory before offering it to others. We’ve found that those who follow our recommendation meet with orchid success!
The type of potting medium being used can also affect your plant's water requirements. Bark has a tendency to dry out more rapidly than sphagnum moss, for instance. It is important to remember, however, that even when the surface of your pot is dry, the root area may remain moist. Poke your finger or a regular wooden pencil an inch into the pot; if it feels moist to the touch or if the pencil looks moist, do not add additional water. The potting medium should always be damp, but not soggy—neither should it be allowed to get extremely dry.
The petals of these orchids are a bit smaller than those of other orchids, and it consists of many spikes so there are a lot of those petals to look at. The Cymbidium orchid has won several international flower awards, and it comes in colors such as yellow and red (the Showoff), lime green (the Chica), and bright pink (the Frae). These and other Cymbidiums are excellent for first-time growers, because they are easy to grow and are low-maintenance. They also do better in cold climates than many other orchids do, and they make beautiful centerpieces.
Epiphytic orchids, those that grow upon a support, have modified aerial roots that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis, called a velamen, has the function of absorbing humidity. It is made of dead cells and can have a silvery-grey, white or brown appearance. In some orchids, the velamen includes spongy and fibrous bodies near the passage cells, called tilosomes.
You can readily buy Paphiopedilum at fancy grocery stores, and if you can’t find them, find a fancier store where women shop with little dogs in their bag! While these types of flowers come in girlie soft pink, eye-catching yellow, innocent white and other soft colors, many of them are dark red, brown and green with hairy and warty petals. The infamous Paphiopedilum sanderianum from Borneo has lateral sepals (the side petals) that can hang down 3 feet (1 meter) long! This highly sought-after plant can cost hundreds of dollars. But there are plenty of wonderful Paphiopedilum plants out there that don’t cost an arm and a leg. Learn more about Paphiopedilum orchids.
Water thoroughly. When you do water, do it like you mean it. Different growers have different rules, but many professional growers turn on their sprinklers for 8 or more minutes. Successful home-growers sometimes dunk their plants, pots and all, into a bucket or sink of water. Some varieties, such as vandas, can be left floating in water for a surprisingly long time. The idea is to make sure the velamen is completely saturated. You want tiny droplets hanging on the roots after watering. This means the plant is completely hydrated.