The flower has five lobed sepals and a bell- or funnel-shaped corolla of five petals, yellow in most species.

[3] In lab analyses Allamanda species have yielded several chemical compounds, including iridoid lactones such as allamandin, plumericin, and plumierides.

[citation needed] In analyses, some species have shown some activity against carcinoma cells, pathogenic fungi, and HIV.

[citation needed] In June 2022 a research team in the Gunung Leuser National Park, Sumatra, Indonesia, observed an orangutan chewing the stem and leaves of this plant, locally known as akar kuning, and applying the resulting paste and chewed leaves to a serious wound on its face.

[7][8] In the wild, allamandas grow along riverbanks and other open, sunny areas with adequate rainfall and perpetually moist substrate.

Allamandas have become naturalized throughout the tropics, growing in roadside ditches, abandoned yards, and dumps.