The is a plant genus of the family Asclepiadaceae (traditional classification) and Apocynaceae (phylogenetic classification) consisting of 80-100 species native to tropical America.
The Oxypetalum caeruleum also known as the star of tweedyi caerulea or the South was brought to South America in the nineteenth century by James Tweedie, head gardener of the Royal Botanic Garden Edinburgh.
It is a perennial vine 30 cm to 90 cm, it is necessary fencing and whose velvety foliage is evergreen to -8 °. It spreads by seeds in the greenhouse between 20 ° and 22 °.
Hardy to -10 °, this vine requires a sunny and protected, and a drained soil, poor and dry preferably. Moderate watering and far between.
The opposite leaves sagittate, fleshy and covered with short downy soft touch are attached by a stalk without stipules creeping stem, full, fluffy also of circular section.
Inflorescence axillary, cymose multiparous, has several small flowers (1.5 cm diameter) with each corolla consists of five sepals and five petals in a star.
The flowers are followed by fruit-shaped pod, characteristics of Asclepiadaceae, which contain winged seeds.
In France, Oxypetalum blooms from May to frost, producing porcelain blue flowers (there are other varieties of white or pink) with five petals that can be used for the composition of bouquets, it is necessary to remove the fruit to extend This flowering.