No, it's not a cloud of dancing butterflies - it's a Texan beauty called gaura
A plant that is reminiscent of cloud of dancing butterflies might seem a bit fanciful, but the flowers of gaura actually do seem to float in the air, if not actually to dance. It has a loose structure of very slender flowering stems that hold a scattering of flowers at their tip, opening fresh flowers in sequence. It is native to the plains of Texas and adjoining areas.
Gaura sends up its stiff stems from a tough woody root, forming a rounded bush-like structure.
The stems later produce a slender flower stem, often arching upwards. It is related to fuchsia and to the weed called willowherb, the relationship to the latter being very obvious. The stems are wiry and tough, but elegant and graceful at the same time.
The flowers are produced continually from summer well into autumn, although the early flushes and late flushes of flowers are usually best.
It is great value in autumn, having a somewhat faded appearance that suits the season very well. Few border perennials flower for a longer period and it is useful as a border flower for that reason.
The flower colours are white and pale pink. The buds show deep pink, opening paler and often turning white before falling.
The flower shape is pretty, vaguely butterfly-shaped, four large petals, often with two on top and a scatter of long trailing stamens. There is considerable variation of colour, and there are some named varieties.
'Siskiyou Pink' is a popular pink variety. Aptly named 'Whirling Butterflies' has palest pink petals with hot pink buds.
'Crimson Butterflies' has rich, soft carmine flowers. 'Rosy Jane' has raspberry pink on the edges of the petals, fading white towards the centre. 'Cherry Brandy' has warm pink flowers and pink buds.
Gaura likes well-drained soil in full sunshine and it is tolerant of heat and relatively dry soil. While it can cope with dry soil, it likes the soil to hold enough moisture in summer and will grow and flower better if this is the case.
It may not be long-lived, especially if the garden is windy and the plant is rocked by gales. It also hates its roots to be waterlogged in winter, as this causes roots to rot and the plant to wither. It can be grown as a greenhouse plant, revelling in the extra warmth.
It is hardy and can be raised from seeds and from cuttings from basal shoots of existing plants.
It is sometimes sold in garden centres. It can look rather spindly as a young plant, but do not let that put you off if you see it for sale because it will soon bulk up when it gets into the open ground.