Cestrum is a genus of plant that is thought to contain anywhere up to 250 different species. Most species of Cestrum are found in tropical areas of the Americas. Plants contained within the genus are usually small or medium-sized shrubs, with some growing to a maximum of 13 feet (3.96 meters). All species of the genus are toxic for humans to eat.
Although it is not known exactly how many species make up the Cestrum genus, it is thought that there is a minimum of 150 and maximum of 250. All the species belong to the Solanaceae family. Aside from its proper name, the genus is also known as jessamine. This is due to the flowers fragrance, which is said to be like jasmine.
As there are a large number of different species, the appearance of the plants varies greatly. There are, however, some similarities between all the species. Most, for example, are evergreen plants, although there are some deciduous species. All the plants require warm and tropical conditions to grow. Species of the genus are found throughout the Americas, from southern regions of Chile up to the southern United States.
There are several species of Cestrum that are grown for ornamental purposes. This partly due to the plants appearance, but also because of the strong smelling flowers. There are other uses of plants in the genus across the world. For example, in Brazil, certain tribes use the plants for spiritual purposes.
The toxic property of all parts of the plants has caused certain species to be labeled pests in some countries. For example, in Australia the green cestrum species is known to kill a large number of livestock each year. This occurs when the livestock eat the leaves of the plant, often from parts of the plant that are already dying.
Despite the toxic nature of the plants, many species play an important role in nature. For example, some species are eaten by caterpillars and are essential for the food chain to function correctly. Some animals may even take the poison from the plants and use it to become toxic to predators.
Some examples of species of the genus include Cestrum parqui, which is sometimes known as green cestrum, and Cestrum diumum which is also known as day blooming jessamine. Species within the genus can be found in a wide range of different areas. Some species are widespread while others are confined to smaller regions.