Epipremnum aureum
Epipremnum aureum is a species of flowering plant in the arum family Araceae, native to Mo'orea in the Society Islands of French Polynesia. The species is a popular houseplant in temperate regions, but has also become naturalised in tropical and sub-tropical forests worldwide, including northern Australia, Southeast Asia, South Asia, the Pacific Islands and the West Indies, where it has caused severe ecological damage in some cases.
The plant has a multitude of common names including golden pothos, Ceylon creeper, hunter's robe, ivy arum, money plant, silver vine, Solomon Islands ivy, marble queen, and taro vine. It is also called devil's vine or devil's ivy because it is almost impossible to kill and it stays green even when kept in the dark. It is sometimes mistakenly labeled as a Philodendron in plant stores. It is commonly known as money plant in many parts of the Indian subcontinent. It rarely flowers without artificial hormone supplements; the last known spontaneous flowering was reported in 1964.
The plant has gained the Royal Horticultural Society's Award of Garden Merit.
History and etymology
This species has been assigned to a number of genera. In 1880 when it was first described, it was named Pothos aureus, which is in part why it is often commonly referred to as a "pothos". After a flower was observed in 1962, it was given the new name of Raphidophora aurea. However, after closer examination of the flower, researchers noticed its heightened similarity to Epipremnum pinnatum and synonymised it with that species. Only after further observations of all parts of the plant, including the leaves and growing patterns, was it again separated from E. pinnatum, as E. aureum.Description
Epipremnum aureum is an evergreen vine growing to tall, with stems up to in diameter, climbing by means of aerial roots which adhere to surfaces. The leaves are alternate, heart-shaped, entire on juvenile plants, but irregularly pinnatifid on mature plants, up to long and broad; juvenile leaves are much smaller, typically under long.The flowers are produced in a spathe up to long. This plant produces trailing stems when it climbs up trees and these take root when they reach the ground and grow along it. The leaves on these trailing stems grow up to long and are the ones normally seen on this plant when it is cultivated as a potted plant.
Shy-flowering nature
While E. aureum is classified as an angiosperm, which typically produce flowers at some point in their life cycle, it is the only reported species in its family that does not develop a flower. Regardless of where this “shy-flowering” plant is grown or what the conditions are like, it will not flower due to a genetic impairment of the gibberellin biosynthetic gene, EaGA3ox1. This impairment causes the plant to be unable to develop bioactive GAs, which is what is responsible for the flowering of plants via the floral meristem identity gene EaLFY. In E. aureum, the floral meristem identity gene expression is absent due to the lack of GAs from EaGA3ox1. It was found that when GAs were experimentally sprayed onto the plant, flowering was induced.Distribution
Originally, it was endemic to the island of Mo'orea from the Society Islands. However, it is now wild in many tropical countries. The following ranges are indicated: Bangladesh, India, Myanmar, Thailand, Vietnam, People's Republic of China, Taiwan, Japan, Malaysia, Singapore, Indonesia, Philippines, Solomon Islands, Vanuatu, New Caledonia, New Guinea, Australia, Marshall Islands, Hawaii, Palau, Fiji, Tonga, Cook Islands and Western Samoa.Cultivation and uses
In temperate regions it is a popular houseplant with numerous cultivars selected for leaves with white, yellow, or light green variegation. It is often used in decorative displays in shopping centers, offices, and other public locations largely because it requires little care and is also attractively leafy. In tropical countries, it is found in many parks and gardens and tends to grow naturally.As an indoor plant it can reach more than 2 m in height if it is given the adequate support, but hardly develops adult-sized leaves. The best results are achieved by providing indirect light; it tolerates an intense luminosity, but long periods of direct sunlight burn the leaves. It lives well with a temperature between. Generally the plant will only need watering when the soil feels dry to the touch. A liquid fertilizer can be added in the spring and it must be replanted every two years. However, it is a very robust plant that supports bad growing conditions. The plant grows rapidly in hydroponic culture.
It can be cultivated from a cutting, a part of a plant used in plant propagation. Cuttings however, can carry various diseases such as Erwina leaf spot, Pythium root rot, Rhizoctonia foot rot, Pseudomonas leaf spot, Southern blight, and Xanthomonas blight.
The plant is also efficient at removing indoor pollutants such as formaldehyde, trichloroethene, toluene, xylene, and benzene. A study found that this effect declined as the molecular weight of the polluting substance increased.
The plant is sometimes used in aquariums, placed on top of the aquarium and allowed to grow roots in the water. This is beneficial to the plant and the aquarium as it absorbs many nitrates and uses them for growth.
Toxicity
The plant is listed as toxic to cats and dogs by the ASPCA, because of the presence of insoluble raphides. Care should be taken to ensure the plant is not consumed by pets. Symptoms may include oral irritation, vomiting, and difficulty in swallowing.Due to the calcium oxalate within the plant, it can be mildly toxic to humans as well. Possible side effects from the consumption of E. aureum are atopic dermatitis as well as burning and/or swelling of the region inside of and surrounding the mouth. Excessive contact with the plant can also lead to general skin irritation.
Invasive species
Epipremnum aureum can become a highly invasive species when introduced into tropical countries where it is not native. In Sri Lanka it overgrows several hectares of the Udawatta Kele Sanctuary in Kandy. Having no natural enemies, it completely overgrows the forest floor as well as the trunks of trees, causing severe ecological disruption.It has also invaded the Kurulukele Forest Reserve in Kegalla, Sri Lanka and other places where it has been planted as a decorative plant, or to hold steep banks along roads. It was included in the Florida Exotic Pest Control Council's 1999 list of invasive species.
A study published in the South African Journal of Botany found the species to be a potential risk of becoming an invasive species along the coasts of South Africa. It suggested a number of different ways to prevent the spreading of the species in the wild, one of which included barring the cultivation of the species outside of an unsupervised area. Additionally, however, the study pointed out that E. aureum cannot propagate on a large scale due to its lack of seed banks as well as its minimal immunity to herbicides. If the plant is maintained in a controlled area, it is not as significant of a threat as when it grows freely in the wild.