Wikidata: Q25308 Wikispecies: Orchidaceae APNI: 54444 EoL: 8156 EPPO: 1ORCF FloraBase: 22787 FNA: 10638 FoAO2: Orchidaceae FoC: 10638 FoIO: orchidaceae Fossilworks: 55864 GBIF: 7689 GRIN: 798 iNaturalist: 47217 IPNI: 30000046-2 IRMNG: 114451 ITIS: 43397 NBN: NBNSYS0000160580 NCBI: 4747 NZOR: f0c1993e-e036-4074-bdae-936c9854ef2b POWO: Tropicos: 42000388 VASCAN: 181 VicFlora: 8b0d8fd4-1b56-449f-a2de-2b153e84399c Watson & Dallwitz: orchidac WoRMS: 414854
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.
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.
A study in the scientific journal Nature has hypothesised that the origin of orchids goes back much longer than originally expected.[14] An extinct species of stingless bee, Proplebeia dominicana, was found trapped in Miocene amber from about 15-20 million years ago. The bee was carrying pollen of a previously unknown orchid taxon, Meliorchis caribea, on its wings. This find is the first evidence of fossilised orchids to date[14] and shows insects were active pollinators of orchids then. This extinct orchid, M. caribea, has been placed within the extant tribe Cranichideae, subtribe Goodyerinae (subfamily Orchidoideae). An even older orchid species, Succinanthera baltica, was described from the Eocene Baltic amber by Poinar & Rasmussen (2017).[15]

The indoor types of orchids, including cattleya and phalaenopsis orchids, produce flowers that last months at a time. When these houseplants start blooming, the flower show continues for a long window—from four to 16 weeks. Cymbidium orchids produce up to 35 flowers per blossom spike, and each spike lasts up to eight weeks. Phalaenopsis orchid flowers can linger from 80 to 120 days.  
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.
If your Catasetum orchid leaves begin to yellow and drop off, do not despair; this deciduous orchid loses its leaves naturally during winter dormancy. There is much variation in appearance between Catasetum species, but one feature they all have in common is the trait of producing male or female flowers, which bear little resemblance to each other. The male flowers have an anatomical trigger that forcefully ejects pollen onto visiting bees.
The amount of drainage your pot has will depend on the size of the pot, with larger pots requiring more drainage holes than smaller pots. Since orchids prefer to grow in smaller pots, a good rule of thumb is to make sure the pot has 4-8 holes if it’s 4 inches (10 centimeters) or so, while larger orchid pots (around 6 inches or 15 centimeters) should have 8-12 holes for drainage.

With the different orchid types, it’s important to master the watering schedule. If orchids have pseudobulbs, enlarged stem structures that store water, the orchid potting mix can dry out a little between waterings. Orchid species that are epiphytes and grow on tree branches in tropical rainforests are adapted to receiving water from daily rain, so they need more frequent watering.  
So you want to grow an orchid? There are tens of thousands of orchid varieties to choose from, in almost every color of the rainbow. Some exotic versions are rarely seen outside specialty shows, while others are readily available to the novice grower. Unlike the common stereotype, many types of orchids will thrive as houseplants, and don’t need to be kept in a greenhouse. The orchid you’ll choose to grow will depend on the environment in your home, as well as the way the plant looks.
The variety of orchid plant types is amazing. Some bloom for weeks at a time, while others keep their flowers an amazing four months or more. Always check the tag that comes with the plant to determine the optimum temperature for your orchid. Choose one that fits in with your normal indoor environment, rather than trying to change your environment to fit the orchid.
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.

Here in Southern California, one orchid that grows extremely well is the boat orchid, Cymbidium. These types of orchids have been grown and depicted in drawings and poetry for more than two thousand years since the time of Confucius. They are still popular plants today because of the big, showy and long-lasting flowers. The pink, yellow, green, red, brown, peach or combination colored flowers also last superbly as cut flowers—if you change water daily and cut back the bottom of the spike, they can look pristine for a month or two in the vase.
If only there was an easy guide or a little water fairy that hovered over your plants and told you exactly when and how much to water. Unfortunately, there isn't. But I think this is one of the satisfying reasons we grow orchids. It's all about balance and instinct—and plenty of patience. Here are some of the factors you need to consider when developing a watering schedule:

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.
Hi. I have a moth orchid that was in bloom when I got it, five years ago. After the blooms dropped off, the flower stock dried out and I cut it off (thought I was supposed to) and it hasn't bloomed since. I thought it would grow a new stock and bloom again the next year. But it hasn't. I'm not experienced with orchids, so am guessing I did the wrong thing by cutting off the stock. Can you give me some direction on this? Is this plant likely to every bloom again? Thank you for any help you can provide.