Encephalartos

Encephalartos aemulans furnas 2015

Encephalartos aemulans 1zz

Encephalartos altensteinii, habitus, Pretoria

Encephalartos Altensteinii

Encephalartos aplanatus furnas 2015

Encephalartos is a genus of cycads found in Africa. These plants are ancient, dating back to the Mesozoic era, and are known for their distinctive appearance, which includes a stout, woody trunk and a crown of large, stiff, evergreen leaves. Encephalartos species are dioecious, meaning they have separate male and female plants, with reproduction occurring through the production of cones rather than flowers. The genus is highly valued for ornamental purposes but faces significant threats from habitat destruction and illegal collection.

Description

Encephalartos species vary greatly in size and form, ranging from small, trunkless plants to large specimens with trunks up to several meters tall. The leaves are pinnate, with a central rachis supporting numerous leaflets, and can be quite long, sometimes reaching several meters in length. The leaflets are often tough and leathery, with sharp points or edges in some species. The color of the leaves can vary from deep green to blue-green, depending on the species.

The reproductive structures of Encephalartos are large, cone-like organs. Male cones are generally cylindrical and produce pollen, while female cones are larger and bear seeds. These cones can be very colorful, with hues ranging from yellow to red, adding to the ornamental value of the plants. After pollination, the seeds develop within the female cone, eventually being released when the cone disintegrates.

Distribution and Habitat

Encephalartos is exclusively found in Africa, with species distributed across various habitats, from dry savannahs to moist forested areas. The range extends from South Africa northwards to Sudan and westwards to Nigeria. These cycads are adapted to a wide range of environmental conditions, but most prefer well-drained soils and sunny locations.

Conservation

Many species of Encephalartos are threatened by habitat loss and over-collecting. The illegal trade in cycads, driven by their desirability as ornamental plants, has led to significant declines in some species. As a result, numerous Encephalartos species are listed on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, with some classified as critically endangered.

Conservation efforts for Encephalartos include both in situ and ex situ strategies. In situ conservation focuses on protecting plants within their natural habitat, often through the establishment of protected areas. Ex situ conservation involves growing plants in botanical gardens or through seed banking, allowing for the preservation of genetic diversity and potentially aiding in future reintroduction efforts.

Cultivation

Encephalartos species are popular in cultivation due to their striking appearance and longevity. They require well-drained soil and can be grown in both full sun and partial shade. While they are relatively slow-growing, they can live for many years, even centuries, with proper care. Watering should be done judiciously, as overwatering can lead to root rot. Cycads are also susceptible to pests such as scale insects and mealybugs.

Ethnobotany

Some species of Encephalartos have been used by indigenous peoples for various purposes. The pith of the trunk, for example, can be processed to produce a type of starch known as cycad flour, which has been used as a food source. However, it is important to note that many parts of cycads are toxic and require special treatment to remove toxins before consumption.

See Also

• Cycad
• Conservation status
• Botanical garden
• Ethnobotany