^ Guillaume Chomicki; Luc P.R. Bidel; Feng Ming; Mario Coiro; Xuan Zhang; Yaofeng Wang; Yves Baissac; Christian Jay-Allemand & Susanne S. Renner (2015). "The velamen protects photosynthetic orchid roots against UV‐B damage, and a large dated phylogeny implies multiple gains and losses of this function during the Cenozoic". New Phytologist. 205 (3): 1330–1341. doi:10.1111/nph.13106.
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.
Catasetum orchids, along with the other members of the Catasetum alliance, have big, thick pseudobulbs with an attractive fan of thin leaves along their length. The flowers can be very showy, but are unisexual, so that male and female flowers look different. Lighting affects which kind appears. They need a dry rest after flowering when the leaves drop.
The medial petal, called the labellum or lip (6), which is always modified and enlarged, is actually the upper medial petal; however, as the flower develops, the inferior ovary (7) or the pedicel usually rotates 180°, so that the labellum arrives at the lower part of the flower, thus becoming suitable to form a platform for pollinators. This characteristic, called resupination, occurs primitively in the family and is considered apomorphic, a derived characteristic all Orchidaceae share. The torsion of the ovary is very evident from the longitudinal section shown (below right). Some orchids have secondarily lost this resupination, e.g. Epidendrum secundum.

Orchids have been used in traditional medicine in an effort to treat many diseases and ailments. They have been used as a source of herbal remedies in China since 2800 BC. Gastrodia elata is one of the three orchids listed in the earliest known Chinese Materia Medica (Shennon bencaojing) (c. 100 AD). Theophrastus mentions orchids in his Enquiry into Plants (372–286 BC).
With a shape that is similar to a dancing lady, the Oncidium orchid is low-maintenance and easy to grow, and it comes in stunning colors such as bright yellow and gold. The variety called Sharry Baby has a chocolate-like scent, and although simple to grow, the Oncidium orchid does require a lot of moisture and humidity to thrive. If you notice any type of deformities in the leaves of this plant, it is likely because this requirement has not been met. They are truly beautiful bloomers.
This site is compiled from photos collected from growers or photo collectors around the world and I rely on them to try to be sure of their identification. As we all know, however, many plants are mislabeled and growers and collectors can't know all species in every genera, so please be advised that to the best of our knowledge the following ID's are correct. I have hundreds of references, thanks to you all, but often many species are not well represented. I try to the best of my capabilities to be correct but as the adage goes, "To err is human". Many species herewith have been scrutinized by taxonomic experts and will be correct, but this may not be true of all the species described. If you have any questions as to the veracity of any species described in this encyclopedia please e-mail me, Jay Pfahl, at jfal@sprynet.com and we will work at correcting the mistake. As to the text it is compiled by culling notes from hundreds of books and publications [See Bibliography and source books] but it too can be wrong in part due to my mistake or in the often conflicting reports on various orchids.
The family encompasses about 6–11% of all seed plants.[4] The largest genera are Bulbophyllum (2,000 species), Epidendrum (1,500 species), Dendrobium (1,400 species) and Pleurothallis (1,000 species). It also includes Vanilla–the genus of the vanilla plant, the type genus Orchis, and many commonly cultivated plants such as Phalaenopsis and Cattleya. Moreover, since the introduction of tropical species into cultivation in the 19th century, horticulturists have produced more than 100,000 hybrids and cultivars.
Also called the Lady’s Slipper orchid, this type of flower is easy to grow and is great for the beginner flower-grower. They come in a wide variety of colors, including cheery colors such as pink, white, and yellow, as well as more somber colors such as brown, burgundy, and near-black tones. In addition, many of the varieties include petals that have bristly hairs, freckles, and even stripes, with an added bonus of specks on some of the varieties’ leaves.
Check your water. For a long time, serious growers insisted that orchids could only be watered with rainwater. Nowadays, most people just use tap water, and this is fine. However, be aware that treated water may have higher salt content, and some water is high in calcium. If you see deposits forming on your plants, you should seek out a new water source.
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).
ust about anything, it sounds simple until you get down to actually doing it, and then the questions come up. But once you get the hang of it, you’ll realize how easy it is. Here are some specifics for successful ice cube watering.One thing you may find yourself wondering is “what size should the ice cubes be?” since there seems to be no standard size or shape anymore. It should melt down to about a ¼ cup of water. As long as that’s the case, the size of the cube is only an issue if it’s crushed ice. The point of using ice cubes is that they melt slowly – releasing the water in a slow drip. So you don’t want to use anything that will melt quickly.
The most important thing to know about how to water phalaenopsis orchids is that you should only water the roots, making sure to leave the crown (leaves, flowers, and stem) dry.  Moisture on these parts of the plant can cause problems such as mold, fungus, and tissue rot – especially if water gets trapped in pockets such as those that form where there’s new growth. If you do get water on any part of the crown, use a paper towel to remove the moisture.
The Sobralia orchid genus grows ubiquitously in much of South and Central America; I've heard them called "ditchweed"! They have beautiful, short-lived flowers whose appearance is somewhat similar to a large Cattleya orchid. Flowers can be more than 6 inches (15cm) across in some species. The plants can get quite large, however, so you need to have enough space for them!
Always water early in the day so that your orchids dry out by nighttime. The proper frequency of watering will depend on the climatic conditions where you live. In general, water once a week during the winter and twice a week when the weather turns warm and dry. The size of your orchid container also helps determine how often you need to water, regardless of climate conditions. Typically, a 6-inch pot needs water every 7 days and a 4-inch pot needs water every 5 to 6 days.