Apocynaceae

Alstonia scholaris by kadavoor

Rhigospira quadrangularis On the Apocynaceae of South America, with some preliminary remarks on the whole family (1878) (20720691296) (cropped)

Acokanthera oblongifolia 2445

Adenium obesum3

Allamanda cathartica flowers 2

Apocynaceae, commonly known as the dogbane family, is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines. This family is significant both ecologically and economically, with many species being used in horticulture and traditional medicine. The Apocynaceae family is notable for its complex chemical makeup, which includes a variety of alkaloids and cardiac glycosides. These compounds have various applications in medicine but also make many of the plants toxic.

Description

Members of the Apocynaceae family are characterized by having milky sap, a feature that is not universal but common. The leaves are usually simple and arranged in opposite pairs or whorls. The flowers are often showy and fragrant, making them attractive for horticulture and pollinators. They typically have five petals, often fused to form a tube-like corolla.

Distribution

The Apocynaceae family is widespread, found in most tropical and subtropical regions of the world, with some species extending into temperate zones. This wide distribution reflects the ecological versatility of the family, with species adapted to a range of habitats from rainforests to arid deserts.

Economic Importance

Several species within the Apocynaceae family are of significant economic importance. For example, species of the genus Vinca are used in the pharmaceutical industry for their alkaloids, which have anti-cancer properties. The Catharanthus roseus, or Madagascar periwinkle, is a well-known source of vinblastine and vincristine. Other genera, such as Nerium and Allamanda, are widely cultivated as ornamental plants.

Toxicity

Many plants in the Apocynaceae family contain toxic compounds, which can be harmful to animals and humans if ingested. The cardiac glycosides found in some species, such as Digitalis, are used therapeutically in small doses but are dangerous in larger quantities.

Conservation

Some species within the Apocynaceae family are considered endangered or vulnerable due to habitat loss, overexploitation, and other environmental pressures. Conservation efforts are essential to preserve the biodiversity and ecological balance of habitats where these plants play integral roles.

Systematics and Evolution

The Apocynaceae family is part of the order Gentianales, closely related to other significant families such as Rubiaceae. Molecular phylogenetic studies have helped clarify the relationships within the family, leading to a better understanding of its evolutionary history and the classification of its members.

Genera

The family includes a large number of genera, some of which are:

• Vinca – Periwinkles
• Nerium – Oleander
• Catharanthus – Madagascar periwinkle
• Allamanda – Golden trumpet
• Mandevilla – Mandevilla
• Tabernaemontana – Crape jasmine

See Also

• Botany
• Medicinal plants
• Horticulture
• Plant conservation