Along with the Asteraceae, they are one of the two largest families of flowering plants. The Orchidaceae have about 28,000 currently accepted species, distributed in about 763 genera.[2][3] The determination of which family is larger is still under debate, because verified data on the members of such enormous families are continually in flux. Regardless, the number of orchid species nearly equals the number of bony fishes and is more than twice the number of bird species, and about four times the number of mammal species.
The Cypripedioideae subfamily is known for its lady slipper orchids, which are named after their slipper-shaped pouches that trap insects and help the flowers get pollinated. There are 5 genera in this subfamily: Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium, and Selenipedium. Cypripedioideae orchids have two lateral, fertile anthers, which is unusual in most other orchids.
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.

A majority of orchids are perennial epiphytes, which grow anchored to trees or shrubs in the tropics and subtropics. Species such as Angraecum sororium are lithophytes,[24] growing on rocks or very rocky soil. Other orchids (including the majority of temperate Orchidaceae) are terrestrial and can be found in habitat areas such as grasslands or forest.
The den-phal type are warm growing year round and do, just by happenstance, bear flowers similar in appearance to the genus Phalaenopsis. They can be distinguished by plant habit (most Dendrobium have pseudobulbs that resemble tall canes) and flower shape. Den-phals have a spur at the back of the lip; some are more pronounced, others less. They are also borne on very strong upright to barely arching stems. Interesting to note, den-phals can rebloom on old canes. 

Great article. I’ve been trying out using hydroponics for my Phals. Doing great so far. One has two new leaves. Apparently Phals are the only orchid hydroponics works with. Found the info on Pinterest. Something different and fun. Note you only leave them in water for three days and then let them dry for a couple of days. Then you put them back in water for three etc. First you clean off all the potting medium then put the bare roots in a jar or other container just large enough for the roots. Then add water.
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.
Phalaenopsis, the Moth Orchid, is one of the most commonly available and easiest to grow orchid genera. It is an especially good choice for beginners to orchid growing. They have large, showy flowers that come in a wide variety of colors. Most species have several flowers per stem, but some have more, and others have as few as one or two. There are a great many hybrid varieties on the market.
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If you are growing your orchid in tree bark or another well-draining medium, you should provide copious amounts of water to soak the roots. After soaking the potting mixture well, allow the excess water to drain out of the pot. This will ensure the return of that all-important airflow to the roots as well as flushing the growing medium to prevent the buildup of mineral salts. Just be sure that you never leave the roots soaking for more than about 15 minutes, as they will start to become waterlogged if you do.
If you just want a quick way to water your orchid without having to transplant the orchid, you can use the ice cube method. Put the equivalent of 1/4 cup (59 ml) of frozen water (usually about three medium ice cubes) on top of the potting mix. Make sure that the ice never comes in contact with the orchid itself - it should only touch the soil. Let the ice cubes melt into the pot. Wait about a week before you do it again. This method is not optimal for the long-term health of the orchid, so only use it as a temporary solution.[2]
The quality of water used, whether for spraying or watering, is of great importance. Since tap water has often been chemically treated, generally with chlorine, it should be used with caution. The best water for orchids is undoubtedly rainwater. Rainwater, as it passes through the air, dissolves and absorbs many substances such as dust, pollen and other organic matter. This enriched rainwater contributes to the nourishment of the plant.
I can control the chances of overwatering by taking them to the sink and letting the water all drain out. That’s the way they get watered in nature as they’re growing on other plants and rocks and those showers blow through. Second, these are tropical plants which like cozy conditions when it comes to temperature. I can’t image they like frozen water melting into them!
Some orchids, such as Neottia and Corallorhiza, lack chlorophyll, so 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.[25] These orchids are known as myco-heterotrophs, but were formerly (incorrectly) described as saprophytes as it was believed 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.

Great article. I’ve been trying out using hydroponics for my Phals. Doing great so far. One has two new leaves. Apparently Phals are the only orchid hydroponics works with. Found the info on Pinterest. Something different and fun. Note you only leave them in water for three days and then let them dry for a couple of days. Then you put them back in water for three etc. First you clean off all the potting medium then put the bare roots in a jar or other container just large enough for the roots. Then add water.


Because these orchids are top-heavy with lots of blooms on each stem, this type of orchid often requires staking. There are over 1,000 species in this category, and they usually come in colors such as white, lavender, or yellow. One of its biggest advantages is the fact that it can grow almost anywhere, regardless of the zone you live in, and some of them keep their leaves all year long. They can also come in more than one color per bloom, which makes them especially attractive.
The den-phal type are warm growing year round and do, just by happenstance, bear flowers similar in appearance to the genus Phalaenopsis. They can be distinguished by plant habit (most Dendrobium have pseudobulbs that resemble tall canes) and flower shape. Den-phals have a spur at the back of the lip; some are more pronounced, others less. They are also borne on very strong upright to barely arching stems. Interesting to note, den-phals can rebloom on old canes.
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