Hybrids

Although there are a few natural hybrids, over 120,000 orchid hybrids have been created by humans, and more are created every year. With numerous subfamilies of closely related orchids, many can be interbred. Expert growers can choose parent plants based on traits they want to emphasize, such as color, shape, or scent. Hybridization can also produce stronger, more resilient plants, with longer lasting and more frequent blooms.

Many commonly grown hybrids are crosses of different species within the same genus. When hybrid parents come from different genera, the species names are combined to indicate the new cross. Examples include:

* Doritaenopsis: a cross between Doritis and Phalaenopsis
* Miltonidium: a cross between Miltonia and Oncidium
* Sophrolaeliocattleya: a 3-way cross between Sophronitis, Laelia, and Cattleya

Hybrids with parents from 4 or more different genera are given a new name that ends with “-ara,” such as Potinara or Wilsonara. The initial part of the name often comes from the name of the grower who created the hybrid.

Where do orchids grow?
Orchids are a global plant family. They grow on all continents except Antarctica, and everywhere but the driest deserts and coldest mountaintops. Many have their homes in tropical rainforests, which is where the most commonly known orchids originate. The rain forests of Central and South America, Africa, and Southeast Asia each contain thousands of different species. Other orchids come from temperate and even polar regions of the world. All European countries and all American states are home to some orchid species. Most orchids native to temperate climates are much smaller and less colorful than their tropical counterparts, and are not typically cultivated.

Orchid Environments
Many orchids do not grow in soil. They grow up in the jungle canopy, where they live as epiphytes (air plants) with their roots attached to tree trunks and limbs. Epiphytic orchids are not parasites, but like ferns and bromeliads, they use their host tree for support. With abundant plant and animal life around them, the rainforest provides fertilizer and water. During dry seasons, high humidity keeps plants from drying out. Most epiphytes are native to the tropics.

Lithophytes grow with their roots attached to rocks. Orchid roots can cling to large rocks or cliff-faces. Some grow in plant debris that collects in crevices. Most lithophytes are also native to the tropics.

Terrestrials grow in the ground in soil, peat, or leaf litter. Many terrestrial orchids grow in damp locations, such as alongside a stream. Some terrestrials are native to the tropics. Most orchid species native to temperate regions of the world are terrestrials.

Orchid plants
With so many thousands of separate species adapted to so many different types of environments, orchid plants come in many different sizes, shapes, and forms. No single description can suffice for such diversity, but there are some common traits:
Orchids follow one of two growth patterns:
• Sympodial, where new growth extends laterally from the old. Examples include Cattleya, Dendrobium, and Maxillaria.
• Monopodial, where new growth extends up a central stem. Examples include Angraecum, Phalaenopsis, and Vanda.
• Many orchids live in areas that experience dry periods, and therefore they may have thick, succulent leaves capable of storing water. Some sympodial orchids have thickened stems at the bases of their leaves, called pseudobulbs, which hold water. Pseudobulbs can be egg-shaped, spherical, or resemble swollen stems.
• Many orchids have roots covered with velamen, a highly absorbent layer of tissue that helps absorb moisture and nutrients. Newly-grown velamen is shiny, with a white or light green color.

Terrestrial orchids from temperate climates often have swollen underground roots, or tubers, to store water and nutrients during dormancy. Leaves and stems die back, and are re-grown each year.