The growth pattern of orchids

Epiphytic orchid

There are the most species of orchids in the tropics, most of which are aerial plants or, more accurately, epiphytes. They grow on tree trunks but do not absorb nutrients from trees; some species are epiphytic on rocks or cliffs. These epiphytic orchids rely on their stout roots attached to tree trunks and rocky surfaces, most or all of which are exposed in the air. Bare rocks provide very little nutrients to plants, which proves that these orchids are not parasites.

The water and nutrients needed for these epiphytic orchids are taken from the inorganic salts contained in Rain Water and Rain Water, and night dew and fog can also be used as a source of water. Any small residue, such as fallen leaves, exfoliated bark or even dead insects, can be used as nutrients when it falls around the roots of orchids. These residues are abundant in tropical forests. The common cultivated epiphytic orchids are Cartland, Wandai orchid, Phalaenopsis, Dendrobium, tiger orchid and so on.

Terrestrial orchid

This type of orchid includes almost all orchid species native to cold and temperate regions. There are also many orchids in tropical and subtropical regions that belong to terrestrial orchids. They have green leaves, and their roots grow in a mixture of deciduous, humus and sandy soil, absorbing water and inorganic nutrients from the soil, more like common flowers. There are more or less obvious filamentous root hairs on the roots of terrestrial orchids, but no root hairs on the roots of epiphytic orchids. Most of the common cultivated terrestrial orchids are Paphiopedilum, Cymbidium, Cymbidium and other Chinese orchids and shrimp orchids.

Saprophytic orchid

There is a special way of life, which is different from ordinary plants. Usually grows on decaying plants, such as rotten wood in the ground. Although saprophytes have only a few genera, they grow all over the world, especially in the tropics and subtropics. The famous traditional Chinese medicine Gastrodia elata is one of the saprophytic orchids. It grows in the ground all the year round, and inflorescences are extracted from the ground only when it blossoms. It is now known that Gastrodia elata grows on Armillaria mellea to provide water and nutrients. Gastrodia elata has been cultivated in a large area in China. At present, most of the traditional Chinese medicine Gastrodia elata on the market comes from cultivated Gastrodia elata, which creates a precedent for artificial cultivation of rotten orchids and partly uncovers the mystery of the growth and reproduction of saprophytic orchids.

It should be noted that it is difficult to strictly classify the growth patterns of orchids. Because a typical epiphytic orchid may be forced to live on the ground by chance (such as broken branches or rotten trees), it has many roots growing into the soil like the ground orchid, and all of the roots have root hairs. Some orchids, such as Orchid, Golden Phalaenopsis and some species of Orchid, do not show any preference for epiphytic or terrestrial growth, and can grow into luxuriant plants either on trees or on the soil on the ground.

In addition, there are some orchids that grow in forest soil like real terrestrial orchids in seedling stage, and then develop into epiphytic orchids and grow on tree trunks. Such as Wandai orchid, vanilla and tree orchid. (Lin Qingde, Mu Wei)