Allamanda cathartica L. (Apocynaceae) A strong climber with shiny leaves and bright yellow scented flowers, native of NE South America, Trinidad (rare) and especially abundant in Guyana, growing in mangrove swamps and along lowland streams, flowering most of the year. Stems to 6m or more; leaves to 6cm long, 3cm wide. Flowers, around 12 (in a raceme) on short branches on the ends of shoots or in the leaf axils. An attractive free-flowering species, commonly planted in the tropics and very good in a warm conservatory. ‘Hendersonii’, the form commonly grown in Europe, has larger flowers 12.5cm across; tube 9cm long. Buds can be brownish and the throat has reddish-brown veins; introduced to Europe from Guyana in 1865. The smaller-flowered A. schottii Pohl has a much shorter (12mm long) narrow portion of the floral tube and shorter lobes, which gives the flower a more trumpet-like shape.
Cultivation Easily grown in any soil and warm conditions.
Height to 9m (30ft). USZ 10–11, surviving -1°C (30°F) of overnight frost. Needs ample water in summer.