This tribe is fairly large and consists of four genera — Dendrochilum, Pholidota, Chelonistele, and Coelogyne — and over 300 species. They are native to the tropical and subtropical regions of the Old World. Coelogyne is the most popular genus. Its orchids are characterized by a three-lobed lip that is concave at the base, and a hooded or winged column.
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).
Oncidium, perhaps more accurately the oncidium alliance, are a group of plants from South America that span a wide range of habitats. Inside the oncidium alliance there are a number of genera that hybridize freely to create what we call intergeneric oncidium hybrids. These can come in all sorts of shapes and sizes but are generally characterized by large quantities of small to medium flowers borne on a branched stem that generally forms a Christmas-tree shape. The most commonly identified Oncidium are the yellow “dancing lady” type.
^ Zhang, Guo-Qiang; Liu, Ke-Wei; Li, Zhen; Lohaus, Rolf; Hsiao, Yu-Yun; Niu, Shan-Ce; Wang, Jie-Yu; Lin, Yao-Cheng; Xu, Qing; Chen, Li-Jun; Yoshida, Kouki; Fujiwara, Sumire; Wang, Zhi-Wen; Zhang, Yong-Qiang; Mitsuda, Nobutaka; Wang, Meina; Liu, Guo-Hui; Pecoraro, Lorenzo; Huang, Hui-Xia; Xiao, Xin-Ju; Lin, Min; Wu, Xin-Yi; Wu, Wan-Lin; Chen, You-Yi; Chang, Song-Bin; Sakamoto, Shingo; Ohme-Takagi, Masaru; Yagi, Masafumi; Zeng, Si-Jin; et al. (2017). "The Apostasia genome and the evolution of orchids" (PDF). Nature. 549 (7672): 379–383. doi:10.1038/nature23897. PMID 28902843.
The Epidendroideae subfamily is the most widespread subfamily. It represents more than eighty percent of orchid species, and includes over 10,000 types of orchids. Although members of the Epidendroideae subfamily are present in temperate regions, they are most prevalent in the tropics of the Eastern and Western hemispheres. There orchids typically have single anthers with sub-erect structures.
Cycnoches orchids have unisexual flowers, meaning they have separate male and female flowers which look different (usually just one of the two types of orchid flowers each time it blooms). The flowers are usually make a very dramatic display. After flowering, the leaves drop off and it enters a dry rest; don't water until it starts to grow again or it will rot.
Often a stunning two-toned orchid of bright pink-red and white, this flower is a hybrid that can actually have various freckles and specks, and even other colors, such as orange. The Cattleya orchid are very fragrant, and they are very popular for use in corsages. They grow up to eight inches in width and come in a variety of colors and designs. The flower is also very popular among breeders and collectors, and they do well indoors.
Always use a water breaker (a water diffuser that you attach to the front of your hose to soften the flow of water): For only a few orchids, a sprinkling can with a long spout with a rose (a water diffuser placed on the end of the water-can spout) that has many small holes works well. These devices allow thorough watering without washing out the potting material.
There are over 60 varieties of the Vanilla orchid, and unfortunately, it only blooms for one day, opening in the morning and closing at night. They grow in clusters of 12-20 buds, and they are yellow-green in color and reach approximately six inches in length. Just like their name suggests, you can actually get vanilla from these flowers, and the blooms have a nice vanilla scent as well. They have to be mature in order to flower, which can take two to three years, and they grow up to ten feet in height. They do best in a garden or a greenhouse, but never as an indoor plant, and they need vertical support to grow and thrive.
With ageing, the pseudobulb sheds its leaves and becomes dormant. At this stage, it is often called a backbulb. Backbulbs still hold nutrition for the plant, but then a pseudobulb usually takes over, exploiting the last reserves accumulated in the backbulb, which eventually dies off, too. A pseudobulb typically lives for about five years. Orchids without noticeable pseudobulbs are also said to have growths, an individual component of a sympodial plant.
Grammatophyllum speciosum is the largest type of orchid and grows up to three meters in height. The world’s most expensive orchid, Shenzhen Nongke, sold for $200,000 at an auction in 2005 and is named after the university that developed it for eight years. Sri Lanka’s Kadupul flower, on the other hand, is considered the most priceless because it blooms just once a year in the night and withers before dawn breaks.

If you love watering plants, this type of orchid is for you, because it can tolerate a lot of dampness and regular watering. In fact, this orchid loves water so much that it can even tolerate wet feet. The petals consist of little pouch-like shapes surrounded by a moustache, and it comes in colors that include light green, white, and light burgundy.
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.