The WALA Plant Library
Goldenrod

Synonyms for Goldenrod: Aaron’s rod, European goldenrod, solidago, woundwort, yellowweed
Scientific Name: Solidago virgaurea L.
Family: Compositae/Asteraceae (Daisy family)

Description:

Goldenrod certainly lives up to its name – the bright golden yellow of this perennial is visible from afar. It grows in dry soils, with stems reaching a height of up to one metre. Its yellow inflorescences are 10 to 15 millimetres across and bloom from August to October. They grow all along the upper half of the stem, from a distance resembling a bushy tail. Indeed, in Germany one of the common names of goldenrod is foxtail.
One particular feature makes it easy to identify goldenrod. As with all composite flowers, each inflorescence, although it looks like one flower, is in fact made up of several individual florets. The tubular disc-florets that make up the middle of these composite flowers are surrounded by long flat ligulate ray-florets which reach outwards. In the composites, this ring of ray florets is normally closed, with no gaps, as in the familiar sunflower or daisy. But in goldenrod every other ray floret petal is missing, and the ring therefore has gaps. However, this is not immediately obvious, because a ray floret petal of the neighbouring flower fills each gap. Thus the interlocking goldenrod flowers together form a thick mass of blooms.
The European goldenrod is similar to the Canadian goldenrod (Solidago Canadensis) which was introduced to Europe in the 19th century and likes to colonise the margins of woodlands, the banks of lakes and railway embankments. But the Canadian species is bigger than our own native version and has smaller flowers which are arranged in tapering panicles.