Since all these "blacks" are actually dark purples and maroons, plan to intersperse plenty of white-flowered plants among them.

Eupatorium in the revised sense (about 42 species of white-flowered plants from the temperate Northern hemisphere) is apparently a close relative of Eutrochium.

However these flowers do not breed true and in the F2 generation red, pink, and white-flowered plants are produced in the ratio 1:2:1.

The flowers emerge in late summer; in wild plants these are normally mauve, but white-flowered plants also occur occasionally.

The flowers are deep purple-blue to lavender with pale centers, and white-flowered plants are known.

Populations often contain both white-flowered and pink-flowered plants.

The flowers have been selected for variations in colour, with dark purple, red and white-flowered plants available in addition to the colours found in wild plants.

Also, when red-flowered plants are crossed with white-flowered plants, pink-flowered offspring, not red, are produced.

'Snow Queen', a white-flowered plant, arose spontaneously in Japan in the late 1990s, but does not look dramatically different from a good H. niger.

Although the white sweet alyssum is the most popular, probably more spectacular are edges of combination plantings with the white-flowered plants alternated with the violet-colored forms.