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.
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.
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 email@example.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 complex mechanisms that orchids have evolved to achieve cross-pollination were investigated by Charles Darwin and described in Fertilisation of Orchids (1862). Orchids have developed highly specialized pollination systems, thus the chances of being pollinated are often scarce, so orchid flowers usually remain receptive for very long periods, rendering unpollinated flowers long-lasting in cultivation. Most orchids deliver pollen in a single mass. Each time pollination succeeds, thousands of ovules can be fertilized.
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.
Brassia, Comparettia, Odontoglossum, Polystachya, Cochleanthes, Tolumnia, Trichocentrum, Brassavola, Psychilis CC Image courtesy of Arne and Bent Larsen on Wikimedia Commons | Catasetum, Cymbidium CC Image courtesy of http://www.larsen-twins.dk on Wikimedia Commons | Cephalanthera CC Image courtesy of Sramey on Wikimedia Commons | Dichaea, Eulophia, Galeandra, Trichoglottis, Lycaste, Stanhopea, Caularthron, Domingoa, Prosthechea, Dendrobium, Goodyera, Stenorrhynchos, Pogonia, Gymnadenia CC Image courtesy of Orchi on Wikimedia Commons | Dipodium CC Image courtesy of David Lochlin on Flickr | Ionopsis, Campylocentrum CC Image courtesy of Maarten Sepp on Flickr | Macradenia CC Image courtesy of Maarten Sepp on Flickr | Koellensteinia CC Image courtesy of Alex Popovkin on Flickr | Leochilus CC Image courtesy of Marcos Antonio Campacci on Wikimedia Commons | Oeceoclades, Bletia, Chiloschista, Renanthera, Miltonia, Brachionidium, Cattleya, Lepanthopsis, Nidema, Scaphyglottis, Trichosalpinx, Eria, Coelogyne, Cyclopogon, Eltroplectris, Eurystyles, Platythelys, Prescottia, Psilochilus, Triphora, Paphiopedilum CC Image courtesy of Dalton Holland Baptista on Wikimedia Commons | Oncidium CC Image courtesy of Calyponte on Wikimedia Commons | Arethusa CC Image courtesy of Chris Meloche on Wikimedia Commons | Arundina CC Image courtesy of Kevin Gepford on Wikimedia Commons | Calopogon CC Image courtesy of Bob Peterson on Flickr | Cleisostoma CC Image courtesy of Earth100 on Wikimedia Commons | Dendrophylax CC Image courtesy of Mick Fournier on Wikimedia Commons and CC Image courtesy of Big Cypress National Preserve on Flickr | Micropera, Crepidium CC Image courtesy of Raabbustamante on Wikimedia Commons | Taeniophyllum CC Image courtesy of Airborne Pilot on Flickr | Corallorhiza CC Image courtesy of Wsiegmund on Wikimedia Commons | Maxillaria CC Image courtesy of Walter on Flickr | Govenia CC Image courtesy of Sanfelipe on Wikimedia Commons | Isochilus CC Image courtesy of Patricia Harding on Wikimedia Commons | Lepanthes CC Image courtesy of Quimbaya on Flickr | Elleanthus CC Image courtesy of Philipp Weigell on Wikimedia Commons | Pleurothallis CC Image courtesy of KENPEI on Wikimedia Commons | Restrepiella CC Image courtesy of Moises Béhar on Wikimedia Commons | Bulbophyllum CC Image courtesy of Montrealais on Wikimedia Commons Calanthe CC Image courtesy of Qwert1234 on Wikimedia Commons | Phaius CC Image courtesy of Hectonichus on Wikimedia Commons | Spathoglottis CC Image courtesy of Vaikoovery on Wikimedia Commons | Calypso CC Image courtesy of Walter Siegmund on Wikimedia Commons | Tipularia CC Image courtesy of TheAlphaWolf on Wikimedia Commons | Malaxis CC Image courtesy of Bernd Haynold on Wikimedia Commons | Oberonia CC Image courtesy of Ramesh Meda on Flickr | Anoectochilus CC Image courtesy of Badlydrawnboy22 on Wikimedia Commons | Cranichis CC Image courtesy of Americo Docha Neto on Wikimedia Commons | Mesadenus, Pteroglossaspis CC Image courtesy of NC Orchid on Flickr | Pelexia CC Image courtesy of Elena Gaillard on Wikimedia Commons Ponthieva CC Image courtesy of Jose Lacruz on Wikimedia Commons | Spiranthes CC Image courtesy of Eric in SF on Wikimedia Commons | Zeuxine CC Image courtesy of Panoso on Wikimedia Commons Dactylorhiza CC Image courtesy of Uoaei1 on Wikimedia Commons | Habenaria CC Image courtesy of J.M.Garg on Wikimedia Commons | Ophrys, Pseudorchis CC Image courtesy of Hans Hillewaert on Wikimedia Commons | Orchis CC Image courtesy of Algirdas on Wikimedia Commons | Platanthera CC Image courtesy of Enrico Blasutto on Wikimedia Commons | Epipactis CC Image courtesy of Dcrjsr on Wikimedia Commons | Listera CC Image courtesy of Superior National Forest on Flickr | Sobralia CC Image courtesy of João Medeiros on Flickr | Broughtonia CC Image courtesy of Walter on Flickr Masdevallia CC Image courtesy of trixty on Flickr | Isotria CC Image courtesy of Jason Hollinger on Flickr | Flickingeria CC Image courtesy of Averater on Wikimedia Commons | Cleistesiopsis CC Image courtesy of Charly Lewisw on Wikimedia Commons | Cypripedium montanum CC Image courtesy of Bill Bouton on Flickr | Cypripedium reginae CC Image courtesy of Orchi on Wikimedia Commons | Disperis, Encyclia, Epidendrum, Vanilla planifolia, Vanilla barbellata CC Image courtesy of Malcolm Manners on Flickr | Govenia CC Image courtesy of Bosque Village on Flickr | Psychopsis CC Image courtesy of LadyDragonflyCC – >;< on Flickr | Aplectrum CC Image courtesy of Fritz Flohr Reynolds on Flickr
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.
Some saprophytic orchid species of the group Gastrodia produce potato-like tubers and were consumed as food by native peoples in Australia and can be successfully cultivated, notably Gastrodia sesamoides. Wild stands of these plants can still be found in the same areas as early aboriginal settlements, such as Ku-ring-gai Chase National Park in Australia. Aboriginal peoples located the plants in habitat by observing where bandicoots had scratched in search of the tubers after detecting the plants underground by scent.[Note 1]
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!
Orchid roots are surrounded by a tissue-paper thin membrane called velamen. This multi-purpose membrane soaks up large amounts of water quickly, adheres to rough surfaces, and promotes the exchange of minerals and salts. Like an expensive water meter, orchid velamen is an excellent indicator of your plant's water needs. Dry velamen is white or silvery, and freshly watered velamen is green or mottled (depending on the species).
Once you develop more than a passing interest in orchids, you will quickly notice how diverse this exotic plant family is. Encompassing genera that yield both the vanilla you love to bake with and fragrances you love to wear, each flower has unique characteristics and care requirements. Compare your plants to some of the most commonly cultivated orchids to help you determine what type of orchid you are growing.